()
{
new KeySchemaElement
{
AttributeName = "year",
KeyType = KeyType.HASH,
},
new KeySchemaElement
{
AttributeName = "title",
KeyType = KeyType.RANGE,
},
},
BillingMode = BillingMode.PAY_PER_REQUEST,
});
// Wait until the table is ACTIVE and then report success.
Console.Write("Waiting for table to become active...");
var request = new DescribeTableRequest
{
TableName = response.TableDescription.TableName,
};
TableStatus status;
int sleepDuration = 2000;
do
{
Thread.Sleep(sleepDuration);
var describeTableResponse = await _amazonDynamoDB.DescribeTableAsync(request);
status = describeTableResponse.Table.TableStatus;
Console.Write(".");
}
while (status != "ACTIVE");
return status == TableStatus.ACTIVE;
}
catch (ResourceInUseException ex)
{
Console.WriteLine($"Table {tableName} already exists. {ex.Message}");
throw;
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred while creating table {tableName}. {ex.Message}");
throw;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred while creating table {tableName}. {ex.Message}");
throw;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 Amazon SDK API Reference》**中的 [CreateTable](https://docs.amazonaws.cn/goto/DotNetSDKV4/dynamodb-2012-08-10/CreateTable)。
------
#### [ Bash ]
**Amazon CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
###############################################################################
# function dynamodb_create_table
#
# This function creates an Amazon DynamoDB table.
#
# Parameters:
# -n table_name -- The name of the table to create.
# -a attribute_definitions -- JSON file path of a list of attributes and their types.
# -k key_schema -- JSON file path of a list of attributes and their key types.
#
# Returns:
# 0 - If successful.
# 1 - If it fails.
###############################################################################
function dynamodb_create_table() {
local table_name attribute_definitions key_schema response
local option OPTARG # Required to use getopts command in a function.
#######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_create_table"
echo "Creates an Amazon DynamoDB table with on-demand billing."
echo " -n table_name -- The name of the table to create."
echo " -a attribute_definitions -- JSON file path of a list of attributes and their types."
echo " -k key_schema -- JSON file path of a list of attributes and their key types."
echo ""
}
# Retrieve the calling parameters.
while getopts "n:a:k:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
a) attribute_definitions="${OPTARG}" ;;
k) key_schema="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
if [[ -z "$attribute_definitions" ]]; then
errecho "ERROR: You must provide an attribute definitions json file path the -a parameter."
usage
return 1
fi
if [[ -z "$key_schema" ]]; then
errecho "ERROR: You must provide a key schema json file path the -k parameter."
usage
return 1
fi
iecho "Parameters:\n"
iecho " table_name: $table_name"
iecho " attribute_definitions: $attribute_definitions"
iecho " key_schema: $key_schema"
iecho ""
response=$(aws dynamodb create-table \
--table-name "$table_name" \
--attribute-definitions file://"$attribute_definitions" \
--billing-mode PAY_PER_REQUEST \
--key-schema file://"$key_schema" )
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports create-table operation failed.$response"
return 1
fi
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function iecho
#
# This function enables the script to display the specified text only if
# the global variable $VERBOSE is set to true.
###############################################################################
function iecho() {
if [[ $VERBOSE == true ]]; then
echo "$@"
fi
}
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《Amazon CLI 命令参考》**中的 [CreateTable](https://docs.amazonaws.cn/goto/aws-cli/dynamodb-2012-08-10/CreateTable)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
//! Create an Amazon DynamoDB table.
/*!
\sa createTable()
\param tableName: Name for the DynamoDB table.
\param primaryKey: Primary key for the DynamoDB table.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::createTable(const Aws::String &tableName,
const Aws::String &primaryKey,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
std::cout << "Creating table " << tableName <<
" with a simple primary key: \"" << primaryKey << "\"." << std::endl;
Aws::DynamoDB::Model::CreateTableRequest request;
Aws::DynamoDB::Model::AttributeDefinition hashKey;
hashKey.SetAttributeName(primaryKey);
hashKey.SetAttributeType(Aws::DynamoDB::Model::ScalarAttributeType::S);
request.AddAttributeDefinitions(hashKey);
Aws::DynamoDB::Model::KeySchemaElement keySchemaElement;
keySchemaElement.WithAttributeName(primaryKey).WithKeyType(
Aws::DynamoDB::Model::KeyType::HASH);
request.AddKeySchema(keySchemaElement);
Aws::DynamoDB::Model::ProvisionedThroughput throughput;
throughput.WithReadCapacityUnits(5).WithWriteCapacityUnits(5);
request.SetProvisionedThroughput(throughput);
request.SetTableName(tableName);
const Aws::DynamoDB::Model::CreateTableOutcome &outcome = dynamoClient.CreateTable(
request);
if (outcome.IsSuccess()) {
std::cout << "Table \""
<< outcome.GetResult().GetTableDescription().GetTableName() <<
" created!" << std::endl;
}
else {
std::cerr << "Failed to create table: " << outcome.GetError().GetMessage()
<< std::endl;
return false;
}
return waitTableActive(tableName, dynamoClient);
}
```
等待表变为活动状态的代码。
```
//! Query a newly created DynamoDB table until it is active.
/*!
\sa waitTableActive()
\param waitTableActive: The DynamoDB table's name.
\param dynamoClient: A DynamoDB client.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName,
const Aws::DynamoDB::DynamoDBClient &dynamoClient) {
// Repeatedly call DescribeTable until table is ACTIVE.
const int MAX_QUERIES = 20;
Aws::DynamoDB::Model::DescribeTableRequest request;
request.SetTableName(tableName);
int count = 0;
while (count < MAX_QUERIES) {
const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable(
request);
if (result.IsSuccess()) {
Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus();
if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) {
std::this_thread::sleep_for(std::chrono::seconds(1));
}
else {
return true;
}
}
else {
std::cerr << "Error DynamoDB::waitTableActive "
<< result.GetError().GetMessage() << std::endl;
return false;
}
count++;
}
return false;
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 Amazon SDK API Reference》**中的 [CreateTable](https://docs.amazonaws.cn/goto/SdkForCpp/dynamodb-2012-08-10/CreateTable)。
------
#### [ CLI ]
**Amazon CLI**
**示例 1：创建带标签的表**
以下 `create-table` 示例使用指定的属性和键架构创建名为 `MusicCollection` 的表。此表使用预调配的吞吐量，并使用 Amazon 默认拥有的 CMK 进行静态加密。该命令还将标签应用于该表，其键为 `Owner`，值为 `blueTeam`。
```
aws dynamodb create-table \
--table-name MusicCollection \
--attribute-definitions AttributeName=Artist,AttributeType=S AttributeName=SongTitle,AttributeType=S \
--key-schema AttributeName=Artist,KeyType=HASH AttributeName=SongTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5 \
--tags Key=Owner,Value=blueTeam
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "Artist",
"AttributeType": "S"
},
{
"AttributeName": "SongTitle",
"AttributeType": "S"
}
],
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"WriteCapacityUnits": 5,
"ReadCapacityUnits": 5
},
"TableSizeBytes": 0,
"TableName": "MusicCollection",
"TableStatus": "CREATING",
"KeySchema": [
{
"KeyType": "HASH",
"AttributeName": "Artist"
},
{
"KeyType": "RANGE",
"AttributeName": "SongTitle"
}
],
"ItemCount": 0,
"CreationDateTime": "2020-05-26T16:04:41.627000-07:00",
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111"
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 2：在按需模式下创建表**
以下示例使用按需模式（而不是预调配吞吐量模式）创建名为 `MusicCollection` 的表。这对于工作负载不可预测的表很有用。
```
aws dynamodb create-table \
--table-name MusicCollection \
--attribute-definitions AttributeName=Artist,AttributeType=S AttributeName=SongTitle,AttributeType=S \
--key-schema AttributeName=Artist,KeyType=HASH AttributeName=SongTitle,KeyType=RANGE \
--billing-mode PAY_PER_REQUEST
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "Artist",
"AttributeType": "S"
},
{
"AttributeName": "SongTitle",
"AttributeType": "S"
}
],
"TableName": "MusicCollection",
"KeySchema": [
{
"AttributeName": "Artist",
"KeyType": "HASH"
},
{
"AttributeName": "SongTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2020-05-27T11:44:10.807000-07:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 0,
"WriteCapacityUnits": 0
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"BillingModeSummary": {
"BillingMode": "PAY_PER_REQUEST"
}
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 3：创建表并使用客户托管的 CMK 对其进行加密**
以下示例创建一个名为 `MusicCollection` 的表并使用客户托管的 CMK 对其进行加密。
```
aws dynamodb create-table \
--table-name MusicCollection \
--attribute-definitions AttributeName=Artist,AttributeType=S AttributeName=SongTitle,AttributeType=S \
--key-schema AttributeName=Artist,KeyType=HASH AttributeName=SongTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5 \
--sse-specification Enabled=true,SSEType=KMS,KMSMasterKeyId=abcd1234-abcd-1234-a123-ab1234a1b234
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "Artist",
"AttributeType": "S"
},
{
"AttributeName": "SongTitle",
"AttributeType": "S"
}
],
"TableName": "MusicCollection",
"KeySchema": [
{
"AttributeName": "Artist",
"KeyType": "HASH"
},
{
"AttributeName": "SongTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2020-05-27T11:12:16.431000-07:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 5,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"SSEDescription": {
"Status": "ENABLED",
"SSEType": "KMS",
"KMSMasterKeyArn": "arn:aws:kms:us-west-2:123456789012:key/abcd1234-abcd-1234-a123-ab1234a1b234"
}
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 4：创建具有本地二级索引的表**
以下示例使用指定的属性和键架构来创建名为 `MusicCollection` 且其本地二级索引名为 `AlbumTitleIndex` 的表。
```
aws dynamodb create-table \
--table-name MusicCollection \
--attribute-definitions AttributeName=Artist,AttributeType=S AttributeName=SongTitle,AttributeType=S AttributeName=AlbumTitle,AttributeType=S \
--key-schema AttributeName=Artist,KeyType=HASH AttributeName=SongTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--local-secondary-indexes \
"[
{
\"IndexName\": \"AlbumTitleIndex\",
\"KeySchema\": [
{\"AttributeName\": \"Artist\",\"KeyType\":\"HASH\"},
{\"AttributeName\": \"AlbumTitle\",\"KeyType\":\"RANGE\"}
],
\"Projection\": {
\"ProjectionType\": \"INCLUDE\",
\"NonKeyAttributes\": [\"Genre\", \"Year\"]
}
}
]"
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "AlbumTitle",
"AttributeType": "S"
},
{
"AttributeName": "Artist",
"AttributeType": "S"
},
{
"AttributeName": "SongTitle",
"AttributeType": "S"
}
],
"TableName": "MusicCollection",
"KeySchema": [
{
"AttributeName": "Artist",
"KeyType": "HASH"
},
{
"AttributeName": "SongTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2020-05-26T15:59:49.473000-07:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"LocalSecondaryIndexes": [
{
"IndexName": "AlbumTitleIndex",
"KeySchema": [
{
"AttributeName": "Artist",
"KeyType": "HASH"
},
{
"AttributeName": "AlbumTitle",
"KeyType": "RANGE"
}
],
"Projection": {
"ProjectionType": "INCLUDE",
"NonKeyAttributes": [
"Genre",
"Year"
]
},
"IndexSizeBytes": 0,
"ItemCount": 0,
"IndexArn": "arn:aws:dynamodb:us-west-2:123456789012:table/MusicCollection/index/AlbumTitleIndex"
}
]
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 5：创建具有全局二级索引的表**
以下示例创建一个名为 `GameScores` 且其全局二级索引名为 `GameTitleIndex` 的表。基表的分区键为 `UserId`，排序键为 `GameTitle`，可以有效地找到特定游戏的单个用户的最佳分数，而 GSI 则具有分区键 `GameTitle` 和排序键 `TopScore`，允许您快速找到特定游戏的总体最高分。
```
aws dynamodb create-table \
--table-name GameScores \
--attribute-definitions AttributeName=UserId,AttributeType=S AttributeName=GameTitle,AttributeType=S AttributeName=TopScore,AttributeType=N \
--key-schema AttributeName=UserId,KeyType=HASH \
AttributeName=GameTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--global-secondary-indexes \
"[
{
\"IndexName\": \"GameTitleIndex\",
\"KeySchema\": [
{\"AttributeName\":\"GameTitle\",\"KeyType\":\"HASH\"},
{\"AttributeName\":\"TopScore\",\"KeyType\":\"RANGE\"}
],
\"Projection\": {
\"ProjectionType\":\"INCLUDE\",
\"NonKeyAttributes\":[\"UserId\"]
},
\"ProvisionedThroughput\": {
\"ReadCapacityUnits\": 10,
\"WriteCapacityUnits\": 5
}
}
]"
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "GameTitle",
"AttributeType": "S"
},
{
"AttributeName": "TopScore",
"AttributeType": "N"
},
{
"AttributeName": "UserId",
"AttributeType": "S"
}
],
"TableName": "GameScores",
"KeySchema": [
{
"AttributeName": "UserId",
"KeyType": "HASH"
},
{
"AttributeName": "GameTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2020-05-26T17:28:15.602000-07:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"GlobalSecondaryIndexes": [
{
"IndexName": "GameTitleIndex",
"KeySchema": [
{
"AttributeName": "GameTitle",
"KeyType": "HASH"
},
{
"AttributeName": "TopScore",
"KeyType": "RANGE"
}
],
"Projection": {
"ProjectionType": "INCLUDE",
"NonKeyAttributes": [
"UserId"
]
},
"IndexStatus": "CREATING",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"IndexSizeBytes": 0,
"ItemCount": 0,
"IndexArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores/index/GameTitleIndex"
}
]
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 6：一次创建一个具有多个全局二级索引的表**
以下示例创建一个名为 `GameScores` 且具有两个全局二级索引的表。GSI 架构通过文件传递，而不是通过命令行传递。
```
aws dynamodb create-table \
--table-name GameScores \
--attribute-definitions AttributeName=UserId,AttributeType=S AttributeName=GameTitle,AttributeType=S AttributeName=TopScore,AttributeType=N AttributeName=Date,AttributeType=S \
--key-schema AttributeName=UserId,KeyType=HASH AttributeName=GameTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--global-secondary-indexes file://gsi.json
```
的内容`gsi.json`：
```
[
{
"IndexName": "GameTitleIndex",
"KeySchema": [
{
"AttributeName": "GameTitle",
"KeyType": "HASH"
},
{
"AttributeName": "TopScore",
"KeyType": "RANGE"
}
],
"Projection": {
"ProjectionType": "ALL"
},
"ProvisionedThroughput": {
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
}
},
{
"IndexName": "GameDateIndex",
"KeySchema": [
{
"AttributeName": "GameTitle",
"KeyType": "HASH"
},
{
"AttributeName": "Date",
"KeyType": "RANGE"
}
],
"Projection": {
"ProjectionType": "ALL"
},
"ProvisionedThroughput": {
"ReadCapacityUnits": 5,
"WriteCapacityUnits": 5
}
}
]
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "Date",
"AttributeType": "S"
},
{
"AttributeName": "GameTitle",
"AttributeType": "S"
},
{
"AttributeName": "TopScore",
"AttributeType": "N"
},
{
"AttributeName": "UserId",
"AttributeType": "S"
}
],
"TableName": "GameScores",
"KeySchema": [
{
"AttributeName": "UserId",
"KeyType": "HASH"
},
{
"AttributeName": "GameTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2020-08-04T16:40:55.524000-07:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"GlobalSecondaryIndexes": [
{
"IndexName": "GameTitleIndex",
"KeySchema": [
{
"AttributeName": "GameTitle",
"KeyType": "HASH"
},
{
"AttributeName": "TopScore",
"KeyType": "RANGE"
}
],
"Projection": {
"ProjectionType": "ALL"
},
"IndexStatus": "CREATING",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"IndexSizeBytes": 0,
"ItemCount": 0,
"IndexArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores/index/GameTitleIndex"
},
{
"IndexName": "GameDateIndex",
"KeySchema": [
{
"AttributeName": "GameTitle",
"KeyType": "HASH"
},
{
"AttributeName": "Date",
"KeyType": "RANGE"
}
],
"Projection": {
"ProjectionType": "ALL"
},
"IndexStatus": "CREATING",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 5,
"WriteCapacityUnits": 5
},
"IndexSizeBytes": 0,
"ItemCount": 0,
"IndexArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores/index/GameDateIndex"
}
]
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 7：创建启用了 Streams 的表**
以下示例创建一个名为 `GameScores` 且启用了 DynamoDB Streams 的表。每个项的新旧映像都将写入流中。
```
aws dynamodb create-table \
--table-name GameScores \
--attribute-definitions AttributeName=UserId,AttributeType=S AttributeName=GameTitle,AttributeType=S \
--key-schema AttributeName=UserId,KeyType=HASH AttributeName=GameTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--stream-specification StreamEnabled=TRUE,StreamViewType=NEW_AND_OLD_IMAGES
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "GameTitle",
"AttributeType": "S"
},
{
"AttributeName": "UserId",
"AttributeType": "S"
}
],
"TableName": "GameScores",
"KeySchema": [
{
"AttributeName": "UserId",
"KeyType": "HASH"
},
{
"AttributeName": "GameTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2020-05-27T10:49:34.056000-07:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"StreamSpecification": {
"StreamEnabled": true,
"StreamViewType": "NEW_AND_OLD_IMAGES"
},
"LatestStreamLabel": "2020-05-27T17:49:34.056",
"LatestStreamArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores/stream/2020-05-27T17:49:34.056"
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表的基本操作](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html)。
**示例 8：创建启用了 Keys-Only Stream 的表**
以下示例将创建一个名为 `GameScores` 且启用了 DynamoDB Streams 的表。仅将所修改项的键属性写入流中。
```
aws dynamodb create-table \
--table-name GameScores \
--attribute-definitions AttributeName=UserId,AttributeType=S AttributeName=GameTitle,AttributeType=S \
--key-schema AttributeName=UserId,KeyType=HASH AttributeName=GameTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--stream-specification StreamEnabled=TRUE,StreamViewType=KEYS_ONLY
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "GameTitle",
"AttributeType": "S"
},
{
"AttributeName": "UserId",
"AttributeType": "S"
}
],
"TableName": "GameScores",
"KeySchema": [
{
"AttributeName": "UserId",
"KeyType": "HASH"
},
{
"AttributeName": "GameTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2023-05-25T18:45:34.140000+00:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"StreamSpecification": {
"StreamEnabled": true,
"StreamViewType": "KEYS_ONLY"
},
"LatestStreamLabel": "2023-05-25T18:45:34.140",
"LatestStreamArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores/stream/2023-05-25T18:45:34.140",
"DeletionProtectionEnabled": false
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[更改 DynamoDB Streams 的数据捕获](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/Streams.html)。
**示例 9：使用 Standard Infrequent Access 类创建表**
以下示例创建名为 `GameScores` 的表并分配 Standard-Infrequent Access（DynamoDB 标准-IA）表类。此表类针对主要的存储成本进行了优化。
```
aws dynamodb create-table \
--table-name GameScores \
--attribute-definitions AttributeName=UserId,AttributeType=S AttributeName=GameTitle,AttributeType=S \
--key-schema AttributeName=UserId,KeyType=HASH AttributeName=GameTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--table-class STANDARD_INFREQUENT_ACCESS
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "GameTitle",
"AttributeType": "S"
},
{
"AttributeName": "UserId",
"AttributeType": "S"
}
],
"TableName": "GameScores",
"KeySchema": [
{
"AttributeName": "UserId",
"KeyType": "HASH"
},
{
"AttributeName": "GameTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2023-05-25T18:33:07.581000+00:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"TableClassSummary": {
"TableClass": "STANDARD_INFREQUENT_ACCESS"
},
"DeletionProtectionEnabled": false
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[表类](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/HowItWorks.TableClasses.html)。
**示例 10：创建启用了删除保护功能的表**
以下示例创建一个名为 `GameScores` 的表并启用删除保护。
```
aws dynamodb create-table \
--table-name GameScores \
--attribute-definitions AttributeName=UserId,AttributeType=S AttributeName=GameTitle,AttributeType=S \
--key-schema AttributeName=UserId,KeyType=HASH AttributeName=GameTitle,KeyType=RANGE \
--provisioned-throughput ReadCapacityUnits=10,WriteCapacityUnits=5 \
--deletion-protection-enabled
```
输出：
```
{
"TableDescription": {
"AttributeDefinitions": [
{
"AttributeName": "GameTitle",
"AttributeType": "S"
},
{
"AttributeName": "UserId",
"AttributeType": "S"
}
],
"TableName": "GameScores",
"KeySchema": [
{
"AttributeName": "UserId",
"KeyType": "HASH"
},
{
"AttributeName": "GameTitle",
"KeyType": "RANGE"
}
],
"TableStatus": "CREATING",
"CreationDateTime": "2023-05-25T23:02:17.093000+00:00",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"ReadCapacityUnits": 10,
"WriteCapacityUnits": 5
},
"TableSizeBytes": 0,
"ItemCount": 0,
"TableArn": "arn:aws:dynamodb:us-west-2:123456789012:table/GameScores",
"TableId": "a1b2c3d4-5678-90ab-cdef-EXAMPLE11111",
"DeletionProtectionEnabled": true
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[使用删除保护](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html#WorkingWithTables.Basics.DeletionProtection)。
+ 有关 API 详细信息，请参阅《Amazon CLI 命令参考》**中的 [CreateTable](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/create-table.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// CreateMovieTable creates a DynamoDB table with a composite primary key defined as
// a string sort key named `title`, and a numeric partition key named `year`.
// This function uses NewTableExistsWaiter to wait for the table to be created by
// DynamoDB before it returns.
func (basics TableBasics) CreateMovieTable(ctx context.Context) (*types.TableDescription, error) {
var tableDesc *types.TableDescription
table, err := basics.DynamoDbClient.CreateTable(ctx, &dynamodb.CreateTableInput{
AttributeDefinitions: []types.AttributeDefinition{{
AttributeName: aws.String("year"),
AttributeType: types.ScalarAttributeTypeN,
}, {
AttributeName: aws.String("title"),
AttributeType: types.ScalarAttributeTypeS,
}},
KeySchema: []types.KeySchemaElement{{
AttributeName: aws.String("year"),
KeyType: types.KeyTypeHash,
}, {
AttributeName: aws.String("title"),
KeyType: types.KeyTypeRange,
}},
TableName: aws.String(basics.TableName),
BillingMode: types.BillingModePayPerRequest,
})
if err != nil {
log.Printf("Couldn't create table %v. Here's why: %v\n", basics.TableName, err)
} else {
waiter := dynamodb.NewTableExistsWaiter(basics.DynamoDbClient)
err = waiter.Wait(ctx, &dynamodb.DescribeTableInput{
TableName: aws.String(basics.TableName)}, 5*time.Minute)
if err != nil {
log.Printf("Wait for table exists failed. Here's why: %v\n", err)
}
tableDesc = table.TableDescription
log.Printf("Ccreating table test")
}
return tableDesc, err
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 Amazon SDK API Reference》**中的 [CreateTable](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.CreateTable)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import software.amazon.awssdk.core.waiters.WaiterResponse;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeDefinition;
import software.amazon.awssdk.services.dynamodb.model.BillingMode;
import software.amazon.awssdk.services.dynamodb.model.CreateTableRequest;
import software.amazon.awssdk.services.dynamodb.model.CreateTableResponse;
import software.amazon.awssdk.services.dynamodb.model.DescribeTableRequest;
import software.amazon.awssdk.services.dynamodb.model.DescribeTableResponse;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.KeySchemaElement;
import software.amazon.awssdk.services.dynamodb.model.KeyType;
import software.amazon.awssdk.services.dynamodb.model.OnDemandThroughput;
import software.amazon.awssdk.services.dynamodb.model.ProvisionedThroughput;
import software.amazon.awssdk.services.dynamodb.model.ScalarAttributeType;
import software.amazon.awssdk.services.dynamodb.waiters.DynamoDbWaiter;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class CreateTable {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table to create (for example, Music3).
key - The key for the Amazon DynamoDB table (for example, Artist).
""";
if (args.length != 2) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
String key = args[1];
System.out.println("Creating an Amazon DynamoDB table " + tableName + " with a simple primary key: " + key);
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
String result = createTable(ddb, tableName, key);
System.out.println("New table is " + result);
ddb.close();
}
public static String createTable(DynamoDbClient ddb, String tableName, String key) {
DynamoDbWaiter dbWaiter = ddb.waiter();
CreateTableRequest request = CreateTableRequest.builder()
.attributeDefinitions(AttributeDefinition.builder()
.attributeName(key)
.attributeType(ScalarAttributeType.S)
.build())
.keySchema(KeySchemaElement.builder()
.attributeName(key)
.keyType(KeyType.HASH)
.build())
.billingMode(BillingMode.PAY_PER_REQUEST) // DynamoDB automatically scales based on traffic.
.tableName(tableName)
.build();
String newTable;
try {
CreateTableResponse response = ddb.createTable(request);
DescribeTableRequest tableRequest = DescribeTableRequest.builder()
.tableName(tableName)
.build();
// Wait until the Amazon DynamoDB table is created.
WaiterResponse waiterResponse = dbWaiter.waitUntilTableExists(tableRequest);
waiterResponse.matched().response().ifPresent(System.out::println);
newTable = response.tableDescription().tableName();
return newTable;
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
return "";
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Java 2.x API Reference》**中的 [CreateTable](https://docs.amazonaws.cn/goto/SdkForJavaV2/dynamodb-2012-08-10/CreateTable)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import { CreateTableCommand, DynamoDBClient } from "@aws-sdk/client-dynamodb";
const client = new DynamoDBClient({});
export const main = async () => {
const command = new CreateTableCommand({
TableName: "EspressoDrinks",
// For more information about data types,
// see https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.NamingRulesDataTypes.html#HowItWorks.DataTypes and
// https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Programming.LowLevelAPI.html#Programming.LowLevelAPI.DataTypeDescriptors
AttributeDefinitions: [
{
AttributeName: "DrinkName",
AttributeType: "S",
},
],
KeySchema: [
{
AttributeName: "DrinkName",
KeyType: "HASH",
},
],
BillingMode: "PAY_PER_REQUEST",
});
const response = await client.send(command);
console.log(response);
return response;
};
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 Amazon SDK 开发人员指南》[https://docs.amazonaws.cn/sdk-for-javascript/v3/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-creating-a-table](https://docs.amazonaws.cn/sdk-for-javascript/v3/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-creating-a-table)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 Amazon SDK API Reference》**中的 [CreateTable](https://docs.amazonaws.cn/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/CreateTableCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create the DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
var params = {
AttributeDefinitions: [
{
AttributeName: "CUSTOMER_ID",
AttributeType: "N",
},
{
AttributeName: "CUSTOMER_NAME",
AttributeType: "S",
},
],
KeySchema: [
{
AttributeName: "CUSTOMER_ID",
KeyType: "HASH",
},
{
AttributeName: "CUSTOMER_NAME",
KeyType: "RANGE",
},
],
ProvisionedThroughput: {
ReadCapacityUnits: 1,
WriteCapacityUnits: 1,
},
TableName: "CUSTOMER_LIST",
StreamSpecification: {
StreamEnabled: false,
},
};
// Call DynamoDB to create the table
ddb.createTable(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Table Created", data);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 Amazon SDK 开发人员指南》[https://docs.amazonaws.cn/sdk-for-javascript/v2/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-creating-a-table](https://docs.amazonaws.cn/sdk-for-javascript/v2/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-creating-a-table)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 Amazon SDK API Reference》**中的 [CreateTable](https://docs.amazonaws.cn/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/CreateTable)。
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
suspend fun createNewTable(
tableNameVal: String,
key: String,
): String? {
val attDef =
AttributeDefinition {
attributeName = key
attributeType = ScalarAttributeType.S
}
val keySchemaVal =
KeySchemaElement {
attributeName = key
keyType = KeyType.Hash
}
val request =
CreateTableRequest {
attributeDefinitions = listOf(attDef)
keySchema = listOf(keySchemaVal)
billingMode = BillingMode.PayPerRequest
tableName = tableNameVal
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
var tableArn: String
val response = ddb.createTable(request)
ddb.waitUntilTableExists {
// suspend call
tableName = tableNameVal
}
tableArn = response.tableDescription!!.tableArn.toString()
println("Table $tableArn is ready")
return tableArn
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Kotlin API Reference》**中的 [CreateTable](https://sdk.amazonaws.com/kotlin/api/latest/index.html)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
创建表。
```
$tableName = "ddb_demo_table_$uuid";
$service->createTable(
$tableName,
[
new DynamoDBAttribute('year', 'N', 'HASH'),
new DynamoDBAttribute('title', 'S', 'RANGE')
]
);
public function createTable(string $tableName, array $attributes)
{
$keySchema = [];
$attributeDefinitions = [];
foreach ($attributes as $attribute) {
if (is_a($attribute, DynamoDBAttribute::class)) {
$keySchema[] = ['AttributeName' => $attribute->AttributeName, 'KeyType' => $attribute->KeyType];
$attributeDefinitions[] =
['AttributeName' => $attribute->AttributeName, 'AttributeType' => $attribute->AttributeType];
}
}
$this->dynamoDbClient->createTable([
'TableName' => $tableName,
'KeySchema' => $keySchema,
'AttributeDefinitions' => $attributeDefinitions,
'ProvisionedThroughput' => ['ReadCapacityUnits' => 10, 'WriteCapacityUnits' => 10],
]);
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 Amazon SDK API Reference》**中的 [CreateTable](https://docs.amazonaws.cn/goto/SdkForPHPV3/dynamodb-2012-08-10/CreateTable)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：此示例创建一个名为 Thread 的表，该表的主键由“ForumName”（键类型哈希）和“Subject”（键类型范围）组成。用于构造表的架构可以通过管道传输到所示的每个 cmdlet 中，也可以使用 -Schema 参数指定。**
```
$schema = New-DDBTableSchema
$schema | Add-DDBKeySchema -KeyName "ForumName" -KeyDataType "S"
$schema | Add-DDBKeySchema -KeyName "Subject" -KeyType RANGE -KeyDataType "S"
$schema | New-DDBTable -TableName "Thread" -ReadCapacity 10 -WriteCapacity 5
```
**输出：**
```
AttributeDefinitions : {ForumName, Subject}
TableName : Thread
KeySchema : {ForumName, Subject}
TableStatus : CREATING
CreationDateTime : 10/28/2013 4:39:49 PM
ProvisionedThroughput : Amazon.DynamoDBv2.Model.ProvisionedThroughputDescription
TableSizeBytes : 0
ItemCount : 0
LocalSecondaryIndexes : {}
```
**示例 2：此示例创建一个名为 Thread 的表，该表的主键由“ForumName”（键类型哈希）和“Subject”（键类型范围）组成。还定义了本地二级索引。本地二级索引的键将根据表上的主哈希键（ForumName）自动设置。用于构造表的架构可以通过管道传输到所示的每个 cmdlet 中，也可以使用 -Schema 参数指定。**
```
$schema = New-DDBTableSchema
$schema | Add-DDBKeySchema -KeyName "ForumName" -KeyDataType "S"
$schema | Add-DDBKeySchema -KeyName "Subject" -KeyDataType "S"
$schema | Add-DDBIndexSchema -IndexName "LastPostIndex" -RangeKeyName "LastPostDateTime" -RangeKeyDataType "S" -ProjectionType "keys_only"
$schema | New-DDBTable -TableName "Thread" -ReadCapacity 10 -WriteCapacity 5
```
**输出：**
```
AttributeDefinitions : {ForumName, LastPostDateTime, Subject}
TableName : Thread
KeySchema : {ForumName, Subject}
TableStatus : CREATING
CreationDateTime : 10/28/2013 4:39:49 PM
ProvisionedThroughput : Amazon.DynamoDBv2.Model.ProvisionedThroughputDescription
TableSizeBytes : 0
ItemCount : 0
LocalSecondaryIndexes : {LastPostIndex}
```
**示例 3：此示例展示了如何使用单个管道创建一个名为 Thread 的表，该表的主键由“ForumName”（键类型哈希）和“Subject”（键类型范围）以及本地二级索引组成。如果管道或 -Schema 参数中未提供 TableSchema 对象，则 Add-DDBKeySchema 和 Add-DDBIndexSchema 会为您创建一个新的 TableSchema 对象。**
```
New-DDBTableSchema |
Add-DDBKeySchema -KeyName "ForumName" -KeyDataType "S" |
Add-DDBKeySchema -KeyName "Subject" -KeyDataType "S" |
Add-DDBIndexSchema -IndexName "LastPostIndex" `
-RangeKeyName "LastPostDateTime" `
-RangeKeyDataType "S" `
-ProjectionType "keys_only" |
New-DDBTable -TableName "Thread" -ReadCapacity 10 -WriteCapacity 5
```
**输出：**
```
AttributeDefinitions : {ForumName, LastPostDateTime, Subject}
TableName : Thread
KeySchema : {ForumName, Subject}
TableStatus : CREATING
CreationDateTime : 10/28/2013 4:39:49 PM
ProvisionedThroughput : Amazon.DynamoDBv2.Model.ProvisionedThroughputDescription
TableSizeBytes : 0
ItemCount : 0
LocalSecondaryIndexes : {LastPostIndex}
```
+ 有关 API 详细信息，请参阅《Amazon Tools for PowerShell Cmdlet Reference (V4)》**中的 [CreateTable](https://docs.amazonaws.cn/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：此示例创建一个名为 Thread 的表，该表的主键由“ForumName”（键类型哈希）和“Subject”（键类型范围）组成。用于构造表的架构可以通过管道传输到所示的每个 cmdlet 中，也可以使用 -Schema 参数指定。**
```
$schema = New-DDBTableSchema
$schema | Add-DDBKeySchema -KeyName "ForumName" -KeyDataType "S"
$schema | Add-DDBKeySchema -KeyName "Subject" -KeyType RANGE -KeyDataType "S"
$schema | New-DDBTable -TableName "Thread" -ReadCapacity 10 -WriteCapacity 5
```
**输出：**
```
AttributeDefinitions : {ForumName, Subject}
TableName : Thread
KeySchema : {ForumName, Subject}
TableStatus : CREATING
CreationDateTime : 10/28/2013 4:39:49 PM
ProvisionedThroughput : Amazon.DynamoDBv2.Model.ProvisionedThroughputDescription
TableSizeBytes : 0
ItemCount : 0
LocalSecondaryIndexes : {}
```
**示例 2：此示例创建一个名为 Thread 的表，该表的主键由“ForumName”（键类型哈希）和“Subject”（键类型范围）组成。还定义了本地二级索引。本地二级索引的键将根据表上的主哈希键（ForumName）自动设置。用于构造表的架构可以通过管道传输到所示的每个 cmdlet 中，也可以使用 -Schema 参数指定。**
```
$schema = New-DDBTableSchema
$schema | Add-DDBKeySchema -KeyName "ForumName" -KeyDataType "S"
$schema | Add-DDBKeySchema -KeyName "Subject" -KeyDataType "S"
$schema | Add-DDBIndexSchema -IndexName "LastPostIndex" -RangeKeyName "LastPostDateTime" -RangeKeyDataType "S" -ProjectionType "keys_only"
$schema | New-DDBTable -TableName "Thread" -ReadCapacity 10 -WriteCapacity 5
```
**输出：**
```
AttributeDefinitions : {ForumName, LastPostDateTime, Subject}
TableName : Thread
KeySchema : {ForumName, Subject}
TableStatus : CREATING
CreationDateTime : 10/28/2013 4:39:49 PM
ProvisionedThroughput : Amazon.DynamoDBv2.Model.ProvisionedThroughputDescription
TableSizeBytes : 0
ItemCount : 0
LocalSecondaryIndexes : {LastPostIndex}
```
**示例 3：此示例展示了如何使用单个管道创建一个名为 Thread 的表，该表的主键由“ForumName”（键类型哈希）和“Subject”（键类型范围）以及本地二级索引组成。如果管道或 -Schema 参数中未提供 TableSchema 对象，则 Add-DDBKeySchema 和 Add-DDBIndexSchema 会为您创建一个新的 TableSchema 对象。**
```
New-DDBTableSchema |
Add-DDBKeySchema -KeyName "ForumName" -KeyDataType "S" |
Add-DDBKeySchema -KeyName "Subject" -KeyDataType "S" |
Add-DDBIndexSchema -IndexName "LastPostIndex" `
-RangeKeyName "LastPostDateTime" `
-RangeKeyDataType "S" `
-ProjectionType "keys_only" |
New-DDBTable -TableName "Thread" -ReadCapacity 10 -WriteCapacity 5
```
**输出：**
```
AttributeDefinitions : {ForumName, LastPostDateTime, Subject}
TableName : Thread
KeySchema : {ForumName, Subject}
TableStatus : CREATING
CreationDateTime : 10/28/2013 4:39:49 PM
ProvisionedThroughput : Amazon.DynamoDBv2.Model.ProvisionedThroughputDescription
TableSizeBytes : 0
ItemCount : 0
LocalSecondaryIndexes : {LastPostIndex}
```
+ 有关 API 详细信息，请参阅《Amazon Tools for PowerShell Cmdlet Reference (V5)》**中的 [CreateTable](https://docs.amazonaws.cn/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
创建用于存储电影数据的表。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def create_table(self, table_name):
"""
Creates an Amazon DynamoDB table that can be used to store movie data.
The table uses the release year of the movie as the partition key and the
title as the sort key.
:param table_name: The name of the table to create.
:return: The newly created table.
"""
try:
self.table = self.dyn_resource.create_table(
TableName=table_name,
KeySchema=[
{"AttributeName": "year", "KeyType": "HASH"}, # Partition key
{"AttributeName": "title", "KeyType": "RANGE"}, # Sort key
],
AttributeDefinitions=[
{"AttributeName": "year", "AttributeType": "N"},
{"AttributeName": "title", "AttributeType": "S"},
],
BillingMode='PAY_PER_REQUEST',
)
self.table.wait_until_exists()
except ClientError as err:
logger.error(
"Couldn't create table %s. Here's why: %s: %s",
table_name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return self.table
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Python (Boto3) API Reference》**中的 [CreateTable](https://docs.amazonaws.cn/goto/boto3/dynamodb-2012-08-10/CreateTable)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
# Encapsulates an Amazon DynamoDB table of movie data.
class Scaffold
attr_reader :dynamo_resource, :table_name, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table_name = table_name
@table = nil
@logger = Logger.new($stdout)
@logger.level = Logger::DEBUG
end
# Creates an Amazon DynamoDB table that can be used to store movie data.
# The table uses the release year of the movie as the partition key and the
# title as the sort key.
#
# @param table_name [String] The name of the table to create.
# @return [Aws::DynamoDB::Table] The newly created table.
def create_table(table_name)
@table = @dynamo_resource.create_table(
table_name: table_name,
key_schema: [
{ attribute_name: 'year', key_type: 'HASH' }, # Partition key
{ attribute_name: 'title', key_type: 'RANGE' } # Sort key
],
attribute_definitions: [
{ attribute_name: 'year', attribute_type: 'N' },
{ attribute_name: 'title', attribute_type: 'S' }
],
billing_mode: 'PAY_PER_REQUEST'
)
@dynamo_resource.client.wait_until(:table_exists, table_name: table_name)
@table
rescue Aws::DynamoDB::Errors::ServiceError => e
@logger.error("Failed create table #{table_name}:\n#{e.code}: #{e.message}")
raise
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 Amazon SDK API Reference》**中的 [CreateTable](https://docs.amazonaws.cn/goto/SdkForRubyV3/dynamodb-2012-08-10/CreateTable)。
------
#### [ Rust ]
**适用于 Rust 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
pub async fn create_table(
client: &Client,
table: &str,
key: &str,
) -> Result {
let a_name: String = key.into();
let table_name: String = table.into();
let ad = AttributeDefinition::builder()
.attribute_name(&a_name)
.attribute_type(ScalarAttributeType::S)
.build()
.map_err(Error::BuildError)?;
let ks = KeySchemaElement::builder()
.attribute_name(&a_name)
.key_type(KeyType::Hash)
.build()
.map_err(Error::BuildError)?;
let create_table_response = client
.create_table()
.table_name(table_name)
.key_schema(ks)
.attribute_definitions(ad)
.billing_mode(BillingMode::PayPerRequest)
.send()
.await;
match create_table_response {
Ok(out) => {
println!("Added table {} with key {}", table, key);
Ok(out)
}
Err(e) => {
eprintln!("Got an error creating table:");
eprintln!("{}", e);
Err(Error::unhandled(e))
}
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Rust API Reference》**中的 [CreateTable](https://docs.rs/aws-sdk-dynamodb/latest/aws_sdk_dynamodb/client/struct.Client.html#method.create_table)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
DATA(lt_keyschema) = VALUE /aws1/cl_dynkeyschemaelement=>tt_keyschema(
( NEW /aws1/cl_dynkeyschemaelement( iv_attributename = 'year'
iv_keytype = 'HASH' ) )
( NEW /aws1/cl_dynkeyschemaelement( iv_attributename = 'title'
iv_keytype = 'RANGE' ) ) ).
DATA(lt_attributedefinitions) = VALUE /aws1/cl_dynattributedefn=>tt_attributedefinitions(
( NEW /aws1/cl_dynattributedefn( iv_attributename = 'year'
iv_attributetype = 'N' ) )
( NEW /aws1/cl_dynattributedefn( iv_attributename = 'title'
iv_attributetype = 'S' ) ) ).
" Adjust read/write capacities as desired.
DATA(lo_dynprovthroughput) = NEW /aws1/cl_dynprovthroughput(
iv_readcapacityunits = 5
iv_writecapacityunits = 5 ).
oo_result = lo_dyn->createtable(
it_keyschema = lt_keyschema
iv_tablename = iv_table_name
it_attributedefinitions = lt_attributedefinitions
io_provisionedthroughput = lo_dynprovthroughput ).
" Table creation can take some time. Wait till table exists before returning.
lo_dyn->get_waiter( )->tableexists(
iv_max_wait_time = 200
iv_tablename = iv_table_name ).
MESSAGE 'DynamoDB Table' && iv_table_name && 'created.' TYPE 'I'.
" This exception can happen if the table already exists.
CATCH /aws1/cx_dynresourceinuseex INTO DATA(lo_resourceinuseex).
DATA(lv_error) = |"{ lo_resourceinuseex->av_err_code }" - { lo_resourceinuseex->av_err_msg }|.
MESSAGE lv_error TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《Amazon SDK for SAP ABAP API Reference》**中的 [CreateTable](https://docs.amazonaws.cn/sdk-for-sap-abap/v1/api/latest/index.html)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
///
/// Create a movie table in the Amazon DynamoDB data store.
///
private func createTable() async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = CreateTableInput(
attributeDefinitions: [
DynamoDBClientTypes.AttributeDefinition(attributeName: "year", attributeType: .n),
DynamoDBClientTypes.AttributeDefinition(attributeName: "title", attributeType: .s)
],
billingMode: DynamoDBClientTypes.BillingMode.payPerRequest,
keySchema: [
DynamoDBClientTypes.KeySchemaElement(attributeName: "year", keyType: .hash),
DynamoDBClientTypes.KeySchemaElement(attributeName: "title", keyType: .range)
],
tableName: self.tableName
)
let output = try await client.createTable(input: input)
if output.tableDescription == nil {
throw MoviesError.TableNotFound
}
} catch {
print("ERROR: createTable:", dump(error))
throw error
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Swift API 参考》**中的 [CreateTable](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/createtable(input:))。
------
有关更多 DynamoDB 示例，请参阅[适用于使用 Amazon SDK 的 DynamoDB 的代码示例](service_code_examples.md)。
创建新表后，继续完成 [第 2 步：将数据写入 DynamoDB 表](getting-started-step-2.md)。
# 第 2 步：将数据写入 DynamoDB 表
在此步骤中，您将多个项目插入到在 [第 1 步：在 DynamoDB 中创建表](getting-started-step-1.md) 中创建的 `Music` 表。
有关写入操作的更多信息，请参阅 [写入项目](WorkingWithItems.md#WorkingWithItems.WritingData)。
## Amazon Web Services 管理控制台
按照这些步骤使用 DynamoDB 控制台向 `Music` 表写入数据。
1. 打开 DynamoDB 控制台：[https://console.aws.amazon.com/dynamodb/](https://console.amazonaws.cn/dynamodb/)。
1. 在左侧导航窗格中，选择 **表**。
1. 在**表**页面上，选择 **Music** 表。
1. 选择 **Explore table items**（浏览表项目）。
1. 在**返回的项目**部分中，选择**创建项目**。
1. 在**创建项目**页面上，执行以下操作，将项目添加到表中：
1. 选择 **Add new attribute (添加新属性)**，然后选择 **Number (数字)**。
1. 对于“属性名称”，输入 **Awards**。
1. 重复此过程来创建 **String** 类型的 **AlbumTitle**。
1. 为项目输入以下值：
1. 对于 **Artist**，输入 **No One You Know**。
1. 对于 **SongTitle**，输入 **Call Me Today**。
1. 对于 **AlbumTitle**，输入 **Somewhat Famous**。
1. 对于 **Awards**，输入 **1**。
1. 选择 **Create Item (创建项目)**。
1. 重复此过程并使用以下值创建另一个项目：
1. 对于 **Artist**，输入 **Acme Band**。
1. 对于 **SongTitle**，输入 **Happy Day**。
1. 对于 **AlbumTitle**，输入 **Songs About Life**。
1. 对于 **Awards**，输入 **10**。
1. 再次执行此操作以创建另一个具有与上一步相同的**艺术家**但其他属性值不同的项目：
1. 对于 **Artist**，输入 **Acme Band**。
1. 对于 **SongTitle**，输入 **PartiQL Rocks**。
1. 对于 **AlbumTitle**，输入 **Another Album Title**。
1. 对于 **Awards**，输入 **8**。
## Amazon CLI
下面的 Amazon CLI 示例在 `Music` 表中创建多个新项目。您可以通过 DynamoDB API 或 [PartiQL](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/ql-reference.html)（一种适用于 DynamoDB 的 SQL 兼容查询语言）执行此操作。
------
#### [ DynamoDB API ]
**Linux**
```
aws dynamodb put-item \
--table-name Music \
--item \
'{"Artist": {"S": "No One You Know"}, "SongTitle": {"S": "Call Me Today"}, "AlbumTitle": {"S": "Somewhat Famous"}, "Awards": {"N": "1"}}'
aws dynamodb put-item \
--table-name Music \
--item \
'{"Artist": {"S": "No One You Know"}, "SongTitle": {"S": "Howdy"}, "AlbumTitle": {"S": "Somewhat Famous"}, "Awards": {"N": "2"}}'
aws dynamodb put-item \
--table-name Music \
--item \
'{"Artist": {"S": "Acme Band"}, "SongTitle": {"S": "Happy Day"}, "AlbumTitle": {"S": "Songs About Life"}, "Awards": {"N": "10"}}'
aws dynamodb put-item \
--table-name Music \
--item \
'{"Artist": {"S": "Acme Band"}, "SongTitle": {"S": "PartiQL Rocks"}, "AlbumTitle": {"S": "Another Album Title"}, "Awards": {"N": "8"}}'
```
**Windows CMD**
```
aws dynamodb put-item ^
--table-name Music ^
--item ^
"{\"Artist\": {\"S\": \"No One You Know\"}, \"SongTitle\": {\"S\": \"Call Me Today\"}, \"AlbumTitle\": {\"S\": \"Somewhat Famous\"}, \"Awards\": {\"N\": \"1\"}}"
aws dynamodb put-item ^
--table-name Music ^
--item ^
"{\"Artist\": {\"S\": \"No One You Know\"}, \"SongTitle\": {\"S\": \"Howdy\"}, \"AlbumTitle\": {\"S\": \"Somewhat Famous\"}, \"Awards\": {\"N\": \"2\"}}"
aws dynamodb put-item ^
--table-name Music ^
--item ^
"{\"Artist\": {\"S\": \"Acme Band\"}, \"SongTitle\": {\"S\": \"Happy Day\"}, \"AlbumTitle\": {\"S\": \"Songs About Life\"}, \"Awards\": {\"N\": \"10\"}}"
aws dynamodb put-item ^
--table-name Music ^
--item ^
"{\"Artist\": {\"S\": \"Acme Band\"}, \"SongTitle\": {\"S\": \"PartiQL Rocks\"}, \"AlbumTitle\": {\"S\": \"Another Album Title\"}, \"Awards\": {\"N\": \"8\"}}"
```
------
#### [ PartiQL for DynamoDB ]
**Linux**
```
aws dynamodb execute-statement --statement "INSERT INTO Music \
VALUE \
{'Artist':'No One You Know','SongTitle':'Call Me Today', 'AlbumTitle':'Somewhat Famous', 'Awards':'1'}"
aws dynamodb execute-statement --statement "INSERT INTO Music \
VALUE \
{'Artist':'No One You Know','SongTitle':'Howdy', 'AlbumTitle':'Somewhat Famous', 'Awards':'2'}"
aws dynamodb execute-statement --statement "INSERT INTO Music \
VALUE \
{'Artist':'Acme Band','SongTitle':'Happy Day', 'AlbumTitle':'Songs About Life', 'Awards':'10'}"
aws dynamodb execute-statement --statement "INSERT INTO Music \
VALUE \
{'Artist':'Acme Band','SongTitle':'PartiQL Rocks', 'AlbumTitle':'Another Album Title', 'Awards':'8'}"
```
**Windows CMD**
```
aws dynamodb execute-statement --statement "INSERT INTO Music VALUE {'Artist':'No One You Know','SongTitle':'Call Me Today', 'AlbumTitle':'Somewhat Famous', 'Awards':'1'}"
aws dynamodb execute-statement --statement "INSERT INTO Music VALUE {'Artist':'No One You Know','SongTitle':'Howdy', 'AlbumTitle':'Somewhat Famous', 'Awards':'2'}"
aws dynamodb execute-statement --statement "INSERT INTO Music VALUE {'Artist':'Acme Band','SongTitle':'Happy Day', 'AlbumTitle':'Songs About Life', 'Awards':'10'}"
aws dynamodb execute-statement --statement "INSERT INTO Music VALUE {'Artist':'Acme Band','SongTitle':'PartiQL Rocks', 'AlbumTitle':'Another Album Title', 'Awards':'8'}"
```
有关使用 PartiQL 写入数据的更多信息，请参阅 [PartiQL 插入语句](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/ql-reference.insert.html)。
------
要详细了解 DynamoDB 中支持的数据类型，请参阅[数据类型](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/HowItWorks.NamingRulesDataTypes.html#HowItWorks.DataTypes)。
要详细了解如何在 JSON 中表示 DynamoDB 数据类型，请参阅[属性值](https://docs.amazonaws.cn/amazondynamodb/latest/APIReference/API_AttributeValue.html)。
## Amazon SDK
以下代码示例显示如何使用 Amazon SDK 向 DynamoDB 表中写入项目。
------
#### [ .NET ]
**适用于 .NET 的 Amazon SDK (v4)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/DynamoDB#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
///
/// Adds a new item to the table.
///
/// A Movie object containing informtation for
/// the movie to add to the table.
/// The name of the table where the item will be added.
/// A Boolean value that indicates the results of adding the item.
public async Task PutItemAsync(Movie newMovie, string tableName)
{
try
{
var item = new Dictionary
{
["title"] = new AttributeValue { S = newMovie.Title },
["year"] = new AttributeValue { N = newMovie.Year.ToString() },
};
var request = new PutItemRequest
{
TableName = tableName,
Item = item,
};
await _amazonDynamoDB.PutItemAsync(request);
return true;
}
catch (ResourceNotFoundException ex)
{
Console.WriteLine($"Table {tableName} was not found. {ex.Message}");
return false;
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred while putting item. {ex.Message}");
throw;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred while putting item. {ex.Message}");
throw;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 Amazon SDK API Reference》**中的 [PutItem](https://docs.amazonaws.cn/goto/DotNetSDKV4/dynamodb-2012-08-10/PutItem)。
------
#### [ Bash ]
**Amazon CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
##############################################################################
# function dynamodb_put_item
#
# This function puts an item into a DynamoDB table.
#
# Parameters:
# -n table_name -- The name of the table.
# -i item -- Path to json file containing the item values.
#
# Returns:
# 0 - If successful.
# 1 - If it fails.
##############################################################################
function dynamodb_put_item() {
local table_name item response
local option OPTARG # Required to use getopts command in a function.
#######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_put_item"
echo "Put an item into a DynamoDB table."
echo " -n table_name -- The name of the table."
echo " -i item -- Path to json file containing the item values."
echo ""
}
while getopts "n:i:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
i) item="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
if [[ -z "$item" ]]; then
errecho "ERROR: You must provide an item with the -i parameter."
usage
return 1
fi
iecho "Parameters:\n"
iecho " table_name: $table_name"
iecho " item: $item"
iecho ""
iecho ""
response=$(aws dynamodb put-item \
--table-name "$table_name" \
--item file://"$item")
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports put-item operation failed.$response"
return 1
fi
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function iecho
#
# This function enables the script to display the specified text only if
# the global variable $VERBOSE is set to true.
###############################################################################
function iecho() {
if [[ $VERBOSE == true ]]; then
echo "$@"
fi
}
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《Amazon CLI 命令参考》**中的 [PutItem](https://docs.amazonaws.cn/goto/aws-cli/dynamodb-2012-08-10/PutItem)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
//! Put an item in an Amazon DynamoDB table.
/*!
\sa putItem()
\param tableName: The table name.
\param artistKey: The artist key. This is the partition key for the table.
\param artistValue: The artist value.
\param albumTitleKey: The album title key.
\param albumTitleValue: The album title value.
\param awardsKey: The awards key.
\param awardsValue: The awards value.
\param songTitleKey: The song title key.
\param songTitleValue: The song title value.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::putItem(const Aws::String &tableName,
const Aws::String &artistKey,
const Aws::String &artistValue,
const Aws::String &albumTitleKey,
const Aws::String &albumTitleValue,
const Aws::String &awardsKey,
const Aws::String &awardsValue,
const Aws::String &songTitleKey,
const Aws::String &songTitleValue,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::PutItemRequest putItemRequest;
putItemRequest.SetTableName(tableName);
putItemRequest.AddItem(artistKey, Aws::DynamoDB::Model::AttributeValue().SetS(
artistValue)); // This is the hash key.
putItemRequest.AddItem(albumTitleKey, Aws::DynamoDB::Model::AttributeValue().SetS(
albumTitleValue));
putItemRequest.AddItem(awardsKey,
Aws::DynamoDB::Model::AttributeValue().SetS(awardsValue));
putItemRequest.AddItem(songTitleKey,
Aws::DynamoDB::Model::AttributeValue().SetS(songTitleValue));
const Aws::DynamoDB::Model::PutItemOutcome outcome = dynamoClient.PutItem(
putItemRequest);
if (outcome.IsSuccess()) {
std::cout << "Successfully added Item!" << std::endl;
}
else {
std::cerr << outcome.GetError().GetMessage() << std::endl;
return false;
}
return waitTableActive(tableName, dynamoClient);
}
```
等待表变为活动状态的代码。
```
//! Query a newly created DynamoDB table until it is active.
/*!
\sa waitTableActive()
\param waitTableActive: The DynamoDB table's name.
\param dynamoClient: A DynamoDB client.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName,
const Aws::DynamoDB::DynamoDBClient &dynamoClient) {
// Repeatedly call DescribeTable until table is ACTIVE.
const int MAX_QUERIES = 20;
Aws::DynamoDB::Model::DescribeTableRequest request;
request.SetTableName(tableName);
int count = 0;
while (count < MAX_QUERIES) {
const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable(
request);
if (result.IsSuccess()) {
Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus();
if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) {
std::this_thread::sleep_for(std::chrono::seconds(1));
}
else {
return true;
}
}
else {
std::cerr << "Error DynamoDB::waitTableActive "
<< result.GetError().GetMessage() << std::endl;
return false;
}
count++;
}
return false;
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 Amazon SDK API Reference》**中的 [PutItem](https://docs.amazonaws.cn/goto/SdkForCpp/dynamodb-2012-08-10/PutItem)。
------
#### [ CLI ]
**Amazon CLI**
**示例 1：向表中添加项**
以下 `put-item` 示例将新项添加到 *MusicCollection* 表中。
```
aws dynamodb put-item \
--table-name MusicCollection \
--item file://item.json \
--return-consumed-capacity TOTAL \
--return-item-collection-metrics SIZE
```
的内容`item.json`：
```
{
"Artist": {"S": "No One You Know"},
"SongTitle": {"S": "Call Me Today"},
"AlbumTitle": {"S": "Greatest Hits"}
}
```
输出：
```
{
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 1.0
},
"ItemCollectionMetrics": {
"ItemCollectionKey": {
"Artist": {
"S": "No One You Know"
}
},
"SizeEstimateRangeGB": [
0.0,
1.0
]
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[写入项](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.WritingData)。
**示例 2：有条件地覆盖表中的项**
仅当 `MusicCollection` 表中的现有项具有值为 `Greatest Hits` 的 `AlbumTitle` 属性时，以下 `put-item` 示例才会覆盖该项。该命令将返回该项先前的值。
```
aws dynamodb put-item \
--table-name MusicCollection \
--item file://item.json \
--condition-expression "#A = :A" \
--expression-attribute-names file://names.json \
--expression-attribute-values file://values.json \
--return-values ALL_OLD
```
的内容`item.json`：
```
{
"Artist": {"S": "No One You Know"},
"SongTitle": {"S": "Call Me Today"},
"AlbumTitle": {"S": "Somewhat Famous"}
}
```
的内容`names.json`：
```
{
"#A": "AlbumTitle"
}
```
的内容`values.json`：
```
{
":A": {"S": "Greatest Hits"}
}
```
输出：
```
{
"Attributes": {
"AlbumTitle": {
"S": "Greatest Hits"
},
"Artist": {
"S": "No One You Know"
},
"SongTitle": {
"S": "Call Me Today"
}
}
}
```
如果键已存在，您应看到以下输出：
```
A client error (ConditionalCheckFailedException) occurred when calling the PutItem operation: The conditional request failed.
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[写入项](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.WritingData)。
+ 有关 API 详细信息，请参阅《Amazon CLI 命令参考》**中的 [PutItem](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/put-item.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// AddMovie adds a movie the DynamoDB table.
func (basics TableBasics) AddMovie(ctx context.Context, movie Movie) error {
item, err := attributevalue.MarshalMap(movie)
if err != nil {
panic(err)
}
_, err = basics.DynamoDbClient.PutItem(ctx, &dynamodb.PutItemInput{
TableName: aws.String(basics.TableName), Item: item,
})
if err != nil {
log.Printf("Couldn't add item to table. Here's why: %v\n", err)
}
return err
}
```
定义本示例中使用的 Movie 结构。
```
import (
"archive/zip"
"bytes"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// Movie encapsulates data about a movie. Title and Year are the composite primary key
// of the movie in Amazon DynamoDB. Title is the sort key, Year is the partition key,
// and Info is additional data.
type Movie struct {
Title string `dynamodbav:"title"`
Year int `dynamodbav:"year"`
Info map[string]interface{} `dynamodbav:"info"`
}
// GetKey returns the composite primary key of the movie in a format that can be
// sent to DynamoDB.
func (movie Movie) GetKey() map[string]types.AttributeValue {
title, err := attributevalue.Marshal(movie.Title)
if err != nil {
panic(err)
}
year, err := attributevalue.Marshal(movie.Year)
if err != nil {
panic(err)
}
return map[string]types.AttributeValue{"title": title, "year": year}
}
// String returns the title, year, rating, and plot of a movie, formatted for the example.
func (movie Movie) String() string {
return fmt.Sprintf("%v\n\tReleased: %v\n\tRating: %v\n\tPlot: %v\n",
movie.Title, movie.Year, movie.Info["rating"], movie.Info["plot"])
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 Amazon SDK API Reference》**中的 [PutItem](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.PutItem)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 [DynamoDbClient](https://docs.amazonaws.cn/sdk-for-java/latest/reference/software/amazon/awssdk/services/dynamodb/DynamoDbClient.html) 将项目放入表中。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.PutItemRequest;
import software.amazon.awssdk.services.dynamodb.model.PutItemResponse;
import software.amazon.awssdk.services.dynamodb.model.ResourceNotFoundException;
import java.util.HashMap;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*
* To place items into an Amazon DynamoDB table using the AWS SDK for Java V2,
* its better practice to use the
* Enhanced Client. See the EnhancedPutItem example.
*/
public class PutItem {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table in which an item is placed (for example, Music3).
key - The key used in the Amazon DynamoDB table (for example, Artist).
keyval - The key value that represents the item to get (for example, Famous Band).
albumTitle - The Album title (for example, AlbumTitle).
AlbumTitleValue - The name of the album (for example, Songs About Life ).
Awards - The awards column (for example, Awards).
AwardVal - The value of the awards (for example, 10).
SongTitle - The song title (for example, SongTitle).
SongTitleVal - The value of the song title (for example, Happy Day).
**Warning** This program will place an item that you specify into a table!
""";
if (args.length != 9) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
String key = args[1];
String keyVal = args[2];
String albumTitle = args[3];
String albumTitleValue = args[4];
String awards = args[5];
String awardVal = args[6];
String songTitle = args[7];
String songTitleVal = args[8];
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
putItemInTable(ddb, tableName, key, keyVal, albumTitle, albumTitleValue, awards, awardVal, songTitle,
songTitleVal);
System.out.println("Done!");
ddb.close();
}
public static void putItemInTable(DynamoDbClient ddb,
String tableName,
String key,
String keyVal,
String albumTitle,
String albumTitleValue,
String awards,
String awardVal,
String songTitle,
String songTitleVal) {
HashMap itemValues = new HashMap<>();
itemValues.put(key, AttributeValue.builder().s(keyVal).build());
itemValues.put(songTitle, AttributeValue.builder().s(songTitleVal).build());
itemValues.put(albumTitle, AttributeValue.builder().s(albumTitleValue).build());
itemValues.put(awards, AttributeValue.builder().s(awardVal).build());
PutItemRequest request = PutItemRequest.builder()
.tableName(tableName)
.item(itemValues)
.build();
try {
PutItemResponse response = ddb.putItem(request);
System.out.println(tableName + " was successfully updated. The request id is "
+ response.responseMetadata().requestId());
} catch (ResourceNotFoundException e) {
System.err.format("Error: The Amazon DynamoDB table \"%s\" can't be found.\n", tableName);
System.err.println("Be sure that it exists and that you've typed its name correctly!");
System.exit(1);
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Java 2.x API Reference》**中的 [PutItem](https://docs.amazonaws.cn/goto/SdkForJavaV2/dynamodb-2012-08-10/PutItem)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
此示例使用文档客户端来简化在 DynamoDB 中处理项目的过程。有关 API 详细信息，请参阅 [PutCommand](https://docs.amazonaws.cn/AWSJavaScriptSDK/v3/latest/Package/-aws-sdk-lib-dynamodb/Class/PutCommand/)。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import { PutCommand, DynamoDBDocumentClient } from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new PutCommand({
TableName: "HappyAnimals",
Item: {
CommonName: "Shiba Inu",
},
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 Amazon SDK API Reference》**中的 [PutItem](https://docs.amazonaws.cn/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/PutItemCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
将项目放入表中。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create the DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
var params = {
TableName: "CUSTOMER_LIST",
Item: {
CUSTOMER_ID: { N: "001" },
CUSTOMER_NAME: { S: "Richard Roe" },
},
};
// Call DynamoDB to add the item to the table
ddb.putItem(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data);
}
});
```
使用 DynamoDB 文档客户端将项目放入表中。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create DynamoDB document client
var docClient = new AWS.DynamoDB.DocumentClient({ apiVersion: "2012-08-10" });
var params = {
TableName: "TABLE",
Item: {
HASHKEY: VALUE,
ATTRIBUTE_1: "STRING_VALUE",
ATTRIBUTE_2: VALUE_2,
},
};
docClient.put(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 Amazon SDK 开发人员指南》[https://docs.amazonaws.cn/sdk-for-javascript/v2/developer-guide/dynamodb-example-table-read-write.html#dynamodb-example-table-read-write-writing-an-item](https://docs.amazonaws.cn/sdk-for-javascript/v2/developer-guide/dynamodb-example-table-read-write.html#dynamodb-example-table-read-write-writing-an-item)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 Amazon SDK API Reference》**中的 [PutItem](https://docs.amazonaws.cn/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/PutItem)。
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
suspend fun putItemInTable(
tableNameVal: String,
key: String,
keyVal: String,
albumTitle: String,
albumTitleValue: String,
awards: String,
awardVal: String,
songTitle: String,
songTitleVal: String,
) {
val itemValues = mutableMapOf()
// Add all content to the table.
itemValues[key] = AttributeValue.S(keyVal)
itemValues[songTitle] = AttributeValue.S(songTitleVal)
itemValues[albumTitle] = AttributeValue.S(albumTitleValue)
itemValues[awards] = AttributeValue.S(awardVal)
val request =
PutItemRequest {
tableName = tableNameVal
item = itemValues
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
ddb.putItem(request)
println(" A new item was placed into $tableNameVal.")
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Kotlin API Reference》**中的 [PutItem](https://sdk.amazonaws.com/kotlin/api/latest/index.html)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
echo "What's the name of the last movie you watched?\n";
while (empty($movieName)) {
$movieName = testable_readline("Movie name: ");
}
echo "And what year was it released?\n";
$movieYear = "year";
while (!is_numeric($movieYear) || intval($movieYear) != $movieYear) {
$movieYear = testable_readline("Year released: ");
}
$service->putItem([
'Item' => [
'year' => [
'N' => "$movieYear",
],
'title' => [
'S' => $movieName,
],
],
'TableName' => $tableName,
]);
public function putItem(array $array)
{
$this->dynamoDbClient->putItem($array);
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 Amazon SDK API Reference》**中的 [PutItem](https://docs.amazonaws.cn/goto/SdkForPHPV3/dynamodb-2012-08-10/PutItem)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：创建一个新项目，或将现有项目替换为新项目。**
```
$item = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
AlbumTitle = 'Somewhat Famous'
Price = 1.94
Genre = 'Country'
CriticRating = 9.0
} | ConvertTo-DDBItem
Set-DDBItem -TableName 'Music' -Item $item
```
+ 有关 API 详细信息，请参阅《Amazon Tools for PowerShell Cmdlet Reference (V4)》**中的 [PutItem](https://docs.amazonaws.cn/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：创建一个新项目，或将现有项目替换为新项目。**
```
$item = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
AlbumTitle = 'Somewhat Famous'
Price = 1.94
Genre = 'Country'
CriticRating = 9.0
} | ConvertTo-DDBItem
Set-DDBItem -TableName 'Music' -Item $item
```
+ 有关 API 详细信息，请参阅《Amazon Tools for PowerShell Cmdlet Reference (V5)》**中的 [PutItem](https://docs.amazonaws.cn/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def add_movie(self, title, year, plot, rating):
"""
Adds a movie to the table.
:param title: The title of the movie.
:param year: The release year of the movie.
:param plot: The plot summary of the movie.
:param rating: The quality rating of the movie.
"""
try:
self.table.put_item(
Item={
"year": year,
"title": title,
"info": {"plot": plot, "rating": Decimal(str(rating))},
}
)
except ClientError as err:
logger.error(
"Couldn't add movie %s to table %s. Here's why: %s: %s",
title,
self.table.name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Python (Boto3) API Reference》**中的 [PutItem](https://docs.amazonaws.cn/goto/boto3/dynamodb-2012-08-10/PutItem)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
class DynamoDBBasics
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamo_resource.table(table_name)
end
# Adds a movie to the table.
#
# @param movie [Hash] The title, year, plot, and rating of the movie.
def add_item(movie)
@table.put_item(
item: {
'year' => movie[:year],
'title' => movie[:title],
'info' => { 'plot' => movie[:plot], 'rating' => movie[:rating] }
}
)
rescue Aws::DynamoDB::Errors::ServiceError => e
puts("Couldn't add movie #{title} to table #{@table.name}. Here's why:")
puts("\t#{e.code}: #{e.message}")
raise
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 Amazon SDK API Reference》**中的 [PutItem](https://docs.amazonaws.cn/goto/SdkForRubyV3/dynamodb-2012-08-10/PutItem)。
------
#### [ Rust ]
**适用于 Rust 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
pub async fn add_item(client: &Client, item: Item, table: &String) -> Result {
let user_av = AttributeValue::S(item.username);
let type_av = AttributeValue::S(item.p_type);
let age_av = AttributeValue::S(item.age);
let first_av = AttributeValue::S(item.first);
let last_av = AttributeValue::S(item.last);
let request = client
.put_item()
.table_name(table)
.item("username", user_av)
.item("account_type", type_av)
.item("age", age_av)
.item("first_name", first_av)
.item("last_name", last_av);
println!("Executing request [{request:?}] to add item...");
let resp = request.send().await?;
let attributes = resp.attributes().unwrap();
let username = attributes.get("username").cloned();
let first_name = attributes.get("first_name").cloned();
let last_name = attributes.get("last_name").cloned();
let age = attributes.get("age").cloned();
let p_type = attributes.get("p_type").cloned();
println!(
"Added user {:?}, {:?} {:?}, age {:?} as {:?} user",
username, first_name, last_name, age, p_type
);
Ok(ItemOut {
p_type,
age,
username,
first_name,
last_name,
})
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Rust API Reference》**中的 [PutItem](https://docs.rs/aws-sdk-dynamodb/latest/aws_sdk_dynamodb/client/struct.Client.html#method.put_item)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
DATA(lo_resp) = lo_dyn->putitem(
iv_tablename = iv_table_name
it_item = it_item ).
MESSAGE '1 row inserted into DynamoDB Table' && iv_table_name TYPE 'I'.
CATCH /aws1/cx_dyncondalcheckfaile00.
MESSAGE 'A condition specified in the operation could not be evaluated.' TYPE 'E'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
CATCH /aws1/cx_dyntransactconflictex.
MESSAGE 'Another transaction is using the item' TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《Amazon SDK for SAP ABAP API Reference》**中的 [PutItem](https://docs.amazonaws.cn/sdk-for-sap-abap/v1/api/latest/index.html)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
/// Add a movie specified as a `Movie` structure to the Amazon DynamoDB
/// table.
///
/// - Parameter movie: The `Movie` to add to the table.
///
func add(movie: Movie) async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
// Get a DynamoDB item containing the movie data.
let item = try await movie.getAsItem()
// Send the `PutItem` request to Amazon DynamoDB.
let input = PutItemInput(
item: item,
tableName: self.tableName
)
_ = try await client.putItem(input: input)
} catch {
print("ERROR: add movie:", dump(error))
throw error
}
}
///
/// Return an array mapping attribute names to Amazon DynamoDB attribute
/// values, representing the contents of the `Movie` record as a DynamoDB
/// item.
///
/// - Returns: The movie item as an array of type
/// `[Swift.String:DynamoDBClientTypes.AttributeValue]`.
///
func getAsItem() async throws -> [Swift.String:DynamoDBClientTypes.AttributeValue] {
// Build the item record, starting with the year and title, which are
// always present.
var item: [Swift.String:DynamoDBClientTypes.AttributeValue] = [
"year": .n(String(self.year)),
"title": .s(self.title)
]
// Add the `info` field with the rating and/or plot if they're
// available.
var details: [Swift.String:DynamoDBClientTypes.AttributeValue] = [:]
if (self.info.rating != nil || self.info.plot != nil) {
if self.info.rating != nil {
details["rating"] = .n(String(self.info.rating!))
}
if self.info.plot != nil {
details["plot"] = .s(self.info.plot!)
}
}
item["info"] = .m(details)
return item
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Swift API 参考》**中的 [PutItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/putitem(input:))。
------
有关更多 DynamoDB 示例，请参阅[适用于使用 Amazon SDK 的 DynamoDB 的代码示例](service_code_examples.md)。
将数据写入表后，继续转到 [第 3 步：从 DynamoDB 表中读取数据](getting-started-step-3.md)。
# 第 3 步：从 DynamoDB 表中读取数据
在此步骤中，您将读取在[第 2 步：将数据写入 DynamoDB 表](getting-started-step-2.md)中创建的一个项目。可以通过指定 `Artist` 和 `SongTitle`，使用 DynamoDB 控制台或 Amazon CLI 从 `Music` 表读取项目。
有关 DynamoDB 中的读取操作的更多信息，请参见 [读取项目](WorkingWithItems.md#WorkingWithItems.ReadingData)。
## Amazon Web Services 管理控制台
按照以下步骤，使用 DynamoDB 控制台从 `Music` 表读取数据。
1. 打开 DynamoDB 控制台：[https://console.aws.amazon.com/dynamodb/](https://console.amazonaws.cn/dynamodb/)。
1. 在左侧导航窗格中，选择 **表**。
1. 在**表**页面上，选择 **Music** 表。
1. 选择**浏览表项目**。
1. 在**返回的项目**部分中，查看存储在表中的项目列表，这些项目按 `Artist` 和 `SongTitle` 排序。列表中的第一项是名为 **Acme Band** 的 **Artist**，其 **SongTitle** 为 **PartiQL Rocks**。
## Amazon CLI
下面的 Amazon CLI 示例更新 `Music` 表的项目。您可以通过 DynamoDB API 或 [PartiQL](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/ql-reference.html)（一种适用于 DynamoDB 的 SQL 兼容查询语言）执行此操作。
------
#### [ DynamoDB API ]
**注意**
DynamoDB 的默认行为是最终一致性读取。下面用 `consistent-read` 参数演示较强的一致性读取。
**Linux**
```
aws dynamodb get-item --consistent-read \
--table-name Music \
--key '{ "Artist": {"S": "Acme Band"}, "SongTitle": {"S": "Happy Day"}}'
```
**Windows CMD**
```
aws dynamodb get-item --consistent-read ^
--table-name Music ^
--key "{\"Artist\": {\"S\": \"Acme Band\"}, \"SongTitle\": {\"S\": \"Happy Day\"}}"
```
使用 `get-item` 返回以下示例结果。
```
{
"Item": {
"AlbumTitle": {
"S": "Songs About Life"
},
"Awards": {
"S": "10"
},
"Artist": {
"S": "Acme Band"
},
"SongTitle": {
"S": "Happy Day"
}
}
}
```
------
#### [ PartiQL for DynamoDB ]
**Linux**
```
aws dynamodb execute-statement --statement "SELECT * FROM Music \
WHERE Artist='Acme Band' AND SongTitle='Happy Day'"
```
**Windows CMD**
```
aws dynamodb execute-statement --statement "SELECT * FROM Music WHERE Artist='Acme Band' AND SongTitle='Happy Day'"
```
使用 PartiQL `Select` 语句返回以下示例结果。
```
{
"Items": [
{
"AlbumTitle": {
"S": "Songs About Life"
},
"Awards": {
"S": "10"
},
"Artist": {
"S": "Acme Band"
},
"SongTitle": {
"S": "Happy Day"
}
}
]
}
```
有关使用 PartiQL 读取数据的更多信息，请参阅 [PartiQL 选择语句](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/ql-reference.SELECT.html)。
------
## Amazon SDK
以下代码示例显示如何使用 Amazon SDK 读取 DynamoDB 表中的项目。
------
#### [ .NET ]
**适用于 .NET 的 Amazon SDK (v4)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/DynamoDB#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
///
/// Gets information about an existing movie from the table.
///
/// A Movie object containing information about
/// the movie to retrieve.
/// The name of the table containing the movie.
/// A Dictionary object containing information about the item
/// retrieved.
public async Task> GetItemAsync(Movie newMovie, string tableName)
{
try
{
var key = new Dictionary
{
["title"] = new AttributeValue { S = newMovie.Title },
["year"] = new AttributeValue { N = newMovie.Year.ToString() },
};
var request = new GetItemRequest
{
Key = key,
TableName = tableName,
};
var response = await _amazonDynamoDB.GetItemAsync(request);
return response.Item;
}
catch (ResourceNotFoundException ex)
{
Console.WriteLine($"Table {tableName} was not found. {ex.Message}");
return new Dictionary();
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred while getting item. {ex.Message}");
throw;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred while getting item. {ex.Message}");
throw;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 Amazon SDK API Reference》**中的 [GetItem](https://docs.amazonaws.cn/goto/DotNetSDKV4/dynamodb-2012-08-10/GetItem)。
------
#### [ Bash ]
**Amazon CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
#############################################################################
# function dynamodb_get_item
#
# This function gets an item from a DynamoDB table.
#
# Parameters:
# -n table_name -- The name of the table.
# -k keys -- Path to json file containing the keys that identify the item to get.
# [-q query] -- Optional JMESPath query expression.
#
# Returns:
# The item as text output.
# And:
# 0 - If successful.
# 1 - If it fails.
############################################################################
function dynamodb_get_item() {
local table_name keys query response
local option OPTARG # Required to use getopts command in a function.
# ######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_get_item"
echo "Get an item from a DynamoDB table."
echo " -n table_name -- The name of the table."
echo " -k keys -- Path to json file containing the keys that identify the item to get."
echo " [-q query] -- Optional JMESPath query expression."
echo ""
}
query=""
while getopts "n:k:q:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
k) keys="${OPTARG}" ;;
q) query="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
if [[ -z "$keys" ]]; then
errecho "ERROR: You must provide a keys json file path the -k parameter."
usage
return 1
fi
if [[ -n "$query" ]]; then
response=$(aws dynamodb get-item \
--table-name "$table_name" \
--key file://"$keys" \
--output text \
--query "$query")
else
response=$(
aws dynamodb get-item \
--table-name "$table_name" \
--key file://"$keys" \
--output text
)
fi
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports get-item operation failed.$response"
return 1
fi
if [[ -n "$query" ]]; then
echo "$response" | sed "/^\t/s/\t//1" # Remove initial tab that the JMSEPath query inserts on some strings.
else
echo "$response"
fi
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《Amazon CLI 命令参考》**中的 [GetItem](https://docs.amazonaws.cn/goto/aws-cli/dynamodb-2012-08-10/GetItem)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
//! Get an item from an Amazon DynamoDB table.
/*!
\sa getItem()
\param tableName: The table name.
\param partitionKey: The partition key.
\param partitionValue: The value for the partition key.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::getItem(const Aws::String &tableName,
const Aws::String &partitionKey,
const Aws::String &partitionValue,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::GetItemRequest request;
// Set up the request.
request.SetTableName(tableName);
request.AddKey(partitionKey,
Aws::DynamoDB::Model::AttributeValue().SetS(partitionValue));
// Retrieve the item's fields and values.
const Aws::DynamoDB::Model::GetItemOutcome &outcome = dynamoClient.GetItem(request);
if (outcome.IsSuccess()) {
// Reference the retrieved fields/values.
const Aws::Map &item = outcome.GetResult().GetItem();
if (!item.empty()) {
// Output each retrieved field and its value.
for (const auto &i: item)
std::cout << "Values: " << i.first << ": " << i.second.GetS()
<< std::endl;
}
else {
std::cout << "No item found with the key " << partitionKey << std::endl;
}
}
else {
std::cerr << "Failed to get item: " << outcome.GetError().GetMessage();
}
return outcome.IsSuccess();
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 Amazon SDK API Reference》**中的 [GetItem](https://docs.amazonaws.cn/goto/SdkForCpp/dynamodb-2012-08-10/GetItem)。
------
#### [ CLI ]
**Amazon CLI**
**示例 1：读取表中的项**
以下 `get-item` 示例将从 `MusicCollection` 表中检索项。该表具有 hash-and-range 主键（`Artist` 和 `SongTitle`），因此，您必须指定这两个属性。该命令还请求有关操作所用的读取容量的信息。
```
aws dynamodb get-item \
--table-name MusicCollection \
--key file://key.json \
--return-consumed-capacity TOTAL
```
的内容`key.json`：
```
{
"Artist": {"S": "Acme Band"},
"SongTitle": {"S": "Happy Day"}
}
```
输出：
```
{
"Item": {
"AlbumTitle": {
"S": "Songs About Life"
},
"SongTitle": {
"S": "Happy Day"
},
"Artist": {
"S": "Acme Band"
}
},
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 0.5
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[读取项](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.ReadingData)。
**示例 2：使用一致性读取来读取项**
以下示例使用强一致性读取从 `MusicCollection` 表中检索项。
```
aws dynamodb get-item \
--table-name MusicCollection \
--key file://key.json \
--consistent-read \
--return-consumed-capacity TOTAL
```
的内容`key.json`：
```
{
"Artist": {"S": "Acme Band"},
"SongTitle": {"S": "Happy Day"}
}
```
输出：
```
{
"Item": {
"AlbumTitle": {
"S": "Songs About Life"
},
"SongTitle": {
"S": "Happy Day"
},
"Artist": {
"S": "Acme Band"
}
},
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 1.0
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[读取项](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.ReadingData)。
**示例 3：检索项的特定属性**
以下示例使用投影表达式仅检索所需项的三个属性。
```
aws dynamodb get-item \
--table-name ProductCatalog \
--key '{"Id": {"N": "102"}}' \
--projection-expression "#T, #C, #P" \
--expression-attribute-names file://names.json
```
的内容`names.json`：
```
{
"#T": "Title",
"#C": "ProductCategory",
"#P": "Price"
}
```
输出：
```
{
"Item": {
"Price": {
"N": "20"
},
"Title": {
"S": "Book 102 Title"
},
"ProductCategory": {
"S": "Book"
}
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[读取项](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.ReadingData)。
+ 有关 API 详细信息，请参阅《Amazon CLI 命令参考》**中的 [GetItem](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/get-item.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// GetMovie gets movie data from the DynamoDB table by using the primary composite key
// made of title and year.
func (basics TableBasics) GetMovie(ctx context.Context, title string, year int) (Movie, error) {
movie := Movie{Title: title, Year: year}
response, err := basics.DynamoDbClient.GetItem(ctx, &dynamodb.GetItemInput{
Key: movie.GetKey(), TableName: aws.String(basics.TableName),
})
if err != nil {
log.Printf("Couldn't get info about %v. Here's why: %v\n", title, err)
} else {
err = attributevalue.UnmarshalMap(response.Item, &movie)
if err != nil {
log.Printf("Couldn't unmarshal response. Here's why: %v\n", err)
}
}
return movie, err
}
```
定义本示例中使用的 Movie 结构。
```
import (
"archive/zip"
"bytes"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// Movie encapsulates data about a movie. Title and Year are the composite primary key
// of the movie in Amazon DynamoDB. Title is the sort key, Year is the partition key,
// and Info is additional data.
type Movie struct {
Title string `dynamodbav:"title"`
Year int `dynamodbav:"year"`
Info map[string]interface{} `dynamodbav:"info"`
}
// GetKey returns the composite primary key of the movie in a format that can be
// sent to DynamoDB.
func (movie Movie) GetKey() map[string]types.AttributeValue {
title, err := attributevalue.Marshal(movie.Title)
if err != nil {
panic(err)
}
year, err := attributevalue.Marshal(movie.Year)
if err != nil {
panic(err)
}
return map[string]types.AttributeValue{"title": title, "year": year}
}
// String returns the title, year, rating, and plot of a movie, formatted for the example.
func (movie Movie) String() string {
return fmt.Sprintf("%v\n\tReleased: %v\n\tRating: %v\n\tPlot: %v\n",
movie.Title, movie.Year, movie.Info["rating"], movie.Info["plot"])
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 Amazon SDK API Reference》**中的 [GetItem](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.GetItem)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 DynamoDbClient 从表中获取项目。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.GetItemRequest;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*
* To get an item from an Amazon DynamoDB table using the AWS SDK for Java V2,
* its better practice to use the
* Enhanced Client, see the EnhancedGetItem example.
*/
public class GetItem {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table from which an item is retrieved (for example, Music3).\s
key - The key used in the Amazon DynamoDB table (for example, Artist).\s
keyval - The key value that represents the item to get (for example, Famous Band).
""";
if (args.length != 3) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
String key = args[1];
String keyVal = args[2];
System.out.format("Retrieving item \"%s\" from \"%s\"\n", keyVal, tableName);
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
getDynamoDBItem(ddb, tableName, key, keyVal);
ddb.close();
}
public static void getDynamoDBItem(DynamoDbClient ddb, String tableName, String key, String keyVal) {
HashMap keyToGet = new HashMap<>();
keyToGet.put(key, AttributeValue.builder()
.s(keyVal)
.build());
GetItemRequest request = GetItemRequest.builder()
.key(keyToGet)
.tableName(tableName)
.build();
try {
// If there is no matching item, GetItem does not return any data.
Map returnedItem = ddb.getItem(request).item();
if (returnedItem.isEmpty())
System.out.format("No item found with the key %s!\n", key);
else {
Set keys = returnedItem.keySet();
System.out.println("Amazon DynamoDB table attributes: \n");
for (String key1 : keys) {
System.out.format("%s: %s\n", key1, returnedItem.get(key1).toString());
}
}
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Java 2.x API Reference》**中的 [GetItem](https://docs.amazonaws.cn/goto/SdkForJavaV2/dynamodb-2012-08-10/GetItem)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
此示例使用文档客户端来简化在 DynamoDB 中处理项目的过程。有关 API 详细信息，请参阅 [GetCommand](https://docs.amazonaws.cn/AWSJavaScriptSDK/v3/latest/Package/-aws-sdk-lib-dynamodb/Class/GetCommand/)。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import { DynamoDBDocumentClient, GetCommand } from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new GetCommand({
TableName: "AngryAnimals",
Key: {
CommonName: "Shoebill",
},
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 Amazon SDK API Reference》**中的 [GetItem](https://docs.amazonaws.cn/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/GetItemCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
从表中获取项目。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create the DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
var params = {
TableName: "TABLE",
Key: {
KEY_NAME: { N: "001" },
},
ProjectionExpression: "ATTRIBUTE_NAME",
};
// Call DynamoDB to read the item from the table
ddb.getItem(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data.Item);
}
});
```
使用 DynamoDB 文档客户端从表中获取项目。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create DynamoDB document client
var docClient = new AWS.DynamoDB.DocumentClient({ apiVersion: "2012-08-10" });
var params = {
TableName: "EPISODES_TABLE",
Key: { KEY_NAME: VALUE },
};
docClient.get(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data.Item);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 Amazon SDK 开发人员指南》[https://docs.amazonaws.cn/sdk-for-javascript/v2/developer-guide/dynamodb-example-dynamodb-utilities.html#dynamodb-example-document-client-get](https://docs.amazonaws.cn/sdk-for-javascript/v2/developer-guide/dynamodb-example-dynamodb-utilities.html#dynamodb-example-document-client-get)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 Amazon SDK API Reference》**中的 [GetItem](https://docs.amazonaws.cn/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/GetItem)。
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
suspend fun getSpecificItem(
tableNameVal: String,
keyName: String,
keyVal: String,
) {
val keyToGet = mutableMapOf()
keyToGet[keyName] = AttributeValue.S(keyVal)
val request =
GetItemRequest {
key = keyToGet
tableName = tableNameVal
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
val returnedItem = ddb.getItem(request)
val numbersMap = returnedItem.item
numbersMap?.forEach { key1 ->
println(key1.key)
println(key1.value)
}
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Kotlin API Reference》**中的 [GetItem](https://sdk.amazonaws.com/kotlin/api/latest/index.html)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
$movie = $service->getItemByKey($tableName, $key);
echo "\nThe movie {$movie['Item']['title']['S']} was released in {$movie['Item']['year']['N']}.\n";
public function getItemByKey(string $tableName, array $key)
{
return $this->dynamoDbClient->getItem([
'Key' => $key['Item'],
'TableName' => $tableName,
]);
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 Amazon SDK API Reference》**中的 [GetItem](https://docs.amazonaws.cn/goto/SdkForPHPV3/dynamodb-2012-08-10/GetItem)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：返回带有分区键 SongTitle 和排序键 Artist 的 DynamoDB 项目。**
```
$key = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
} | ConvertTo-DDBItem
Get-DDBItem -TableName 'Music' -Key $key | ConvertFrom-DDBItem
```
**输出：**
```
Name Value
---- -----
Genre Country
SongTitle Somewhere Down The Road
Price 1.94
Artist No One You Know
CriticRating 9
AlbumTitle Somewhat Famous
```
+ 有关 API 详细信息，请参阅《Amazon Tools for PowerShell Cmdlet Reference (V4)》**中的 [GetItem](https://docs.amazonaws.cn/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：返回带有分区键 SongTitle 和排序键 Artist 的 DynamoDB 项目。**
```
$key = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
} | ConvertTo-DDBItem
Get-DDBItem -TableName 'Music' -Key $key | ConvertFrom-DDBItem
```
**输出：**
```
Name Value
---- -----
Genre Country
SongTitle Somewhere Down The Road
Price 1.94
Artist No One You Know
CriticRating 9
AlbumTitle Somewhat Famous
```
+ 有关 API 详细信息，请参阅《Amazon Tools for PowerShell Cmdlet Reference (V5)》**中的 [GetItem](https://docs.amazonaws.cn/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def get_movie(self, title, year):
"""
Gets movie data from the table for a specific movie.
:param title: The title of the movie.
:param year: The release year of the movie.
:return: The data about the requested movie.
"""
try:
response = self.table.get_item(Key={"year": year, "title": title})
except ClientError as err:
logger.error(
"Couldn't get movie %s from table %s. Here's why: %s: %s",
title,
self.table.name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return response["Item"]
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Python (Boto3) API Reference》**中的 [GetItem](https://docs.amazonaws.cn/goto/boto3/dynamodb-2012-08-10/GetItem)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
class DynamoDBBasics
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamo_resource.table(table_name)
end
# Gets movie data from the table for a specific movie.
#
# @param title [String] The title of the movie.
# @param year [Integer] The release year of the movie.
# @return [Hash] The data about the requested movie.
def get_item(title, year)
@table.get_item(key: { 'year' => year, 'title' => title })
rescue Aws::DynamoDB::Errors::ServiceError => e
puts("Couldn't get movie #{title} (#{year}) from table #{@table.name}:\n")
puts("\t#{e.code}: #{e.message}")
raise
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 Amazon SDK API Reference》**中的 [GetItem](https://docs.amazonaws.cn/goto/SdkForRubyV3/dynamodb-2012-08-10/GetItem)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
oo_item = lo_dyn->getitem(
iv_tablename = iv_table_name
it_key = it_key ).
DATA(lt_attr) = oo_item->get_item( ).
DATA(lo_title) = lt_attr[ key = 'title' ]-value.
DATA(lo_year) = lt_attr[ key = 'year' ]-value.
DATA(lo_rating) = lt_attr[ key = 'rating' ]-value.
MESSAGE 'Movie name is: ' && lo_title->get_s( )
&& 'Movie year is: ' && lo_year->get_n( )
&& 'Moving rating is: ' && lo_rating->get_n( ) TYPE 'I'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《Amazon SDK for SAP ABAP API Reference》**中的 [GetItem](https://docs.amazonaws.cn/sdk-for-sap-abap/v1/api/latest/index.html)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
/// Return a `Movie` record describing the specified movie from the Amazon
/// DynamoDB table.
///
/// - Parameters:
/// - title: The movie's title (`String`).
/// - year: The movie's release year (`Int`).
///
/// - Throws: `MoviesError.ItemNotFound` if the movie isn't in the table.
///
/// - Returns: A `Movie` record with the movie's details.
func get(title: String, year: Int) async throws -> Movie {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = GetItemInput(
key: [
"year": .n(String(year)),
"title": .s(title)
],
tableName: self.tableName
)
let output = try await client.getItem(input: input)
guard let item = output.item else {
throw MoviesError.ItemNotFound
}
let movie = try Movie(withItem: item)
return movie
} catch {
print("ERROR: get:", dump(error))
throw error
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Swift API 参考》**中的 [GetItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/getitem(input:))。
------
有关更多 DynamoDB 示例，请参阅[适用于使用 Amazon SDK 的 DynamoDB 的代码示例](service_code_examples.md)。
要更新表中的数据，请继续 [第 4 步：更新 DynamoDB 表中的数据](getting-started-step-4.md)。
# 第 4 步：更新 DynamoDB 表中的数据
在这一步中，更新在 [第 2 步：将数据写入 DynamoDB 表](getting-started-step-2.md) 中创建的项目。可以使用 DynamoDB 控制台或 Amazon CLI，指定 `Artist`、`SongTitle` 和更新的 `AlbumTitle`，更新 `Music` 表的 `AlbumTitle` 项目。
有关写入操作的更多信息，请参阅 [写入项目](WorkingWithItems.md#WorkingWithItems.WritingData)。
## Amazon Web Services 管理控制台
您可以使用 DynamoDB 控制台更新 `Music` 表的数据。
1. 打开 DynamoDB 控制台：[https://console.aws.amazon.com/dynamodb/](https://console.amazonaws.cn/dynamodb/)。
1. 在左侧导航窗格中，选择 **表**。
1. 从表列表中选择 **Music** 表。
1. 选择**浏览表项目**。
1. 在**返回的项目**中，对于 **Artist** 为 **Acme Band** 并且 **SongTitle** 为 **Happy Day** 的项目行，执行以下操作：
1. 将光标放在名为 **Songs About Life** 的 **AlbumTitle** 上。
1. 选择“编辑”图标。
1. 在**编辑字符串**弹出窗口中，输入 **Songs of Twilight**。
1. 选择**保存**。
**提示**
或者，要更新项目，请在**返回的项目**部分中执行以下操作：
选择名为 **Acme Band** 的 **Artist** 并且 **SongTitle** 为 **Happy Day** 的项目行。
从**操作**下拉列表中，选择**编辑项目**。
对于 **AlbumTitle**，输入 **Songs of Twilight**。
选择**保存并关闭**。
## Amazon CLI
下面的 Amazon CLI 示例更新 `Music` 表的项目。您可以通过 DynamoDB API 或 [PartiQL](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/ql-reference.html)（一种适用于 DynamoDB 的 SQL 兼容查询语言）执行此操作。
------
#### [ DynamoDB API ]
**Linux**
```
aws dynamodb update-item \
--table-name Music \
--key '{ "Artist": {"S": "Acme Band"}, "SongTitle": {"S": "Happy Day"}}' \
--update-expression "SET AlbumTitle = :newval" \
--expression-attribute-values '{":newval":{"S":"Updated Album Title"}}' \
--return-values ALL_NEW
```
**Windows CMD**
```
aws dynamodb update-item ^
--table-name Music ^
--key "{\"Artist\": {\"S\": \"Acme Band\"}, \"SongTitle\": {\"S\": \"Happy Day\"}}" ^
--update-expression "SET AlbumTitle = :newval" ^
--expression-attribute-values "{\":newval\":{\"S\":\"Updated Album Title\"}}" ^
--return-values ALL_NEW
```
使用 `update-item` 将返回以下示例结果，因为已指定 `return-values ALL_NEW`。
```
{
"Attributes": {
"AlbumTitle": {
"S": "Updated Album Title"
},
"Awards": {
"S": "10"
},
"Artist": {
"S": "Acme Band"
},
"SongTitle": {
"S": "Happy Day"
}
}
}
```
------
#### [ PartiQL for DynamoDB ]
**Linux**
```
aws dynamodb execute-statement --statement "UPDATE Music \
SET AlbumTitle='Updated Album Title' \
WHERE Artist='Acme Band' AND SongTitle='Happy Day' \
RETURNING ALL NEW *"
```
**Windows CMD**
```
aws dynamodb execute-statement --statement "UPDATE Music SET AlbumTitle='Updated Album Title' WHERE Artist='Acme Band' AND SongTitle='Happy Day' RETURNING ALL NEW *"
```
使用 `Update` 语句将返回以下示例结果，因为已指定 `RETURNING ALL NEW *`。
```
{
"Items": [
{
"AlbumTitle": {
"S": "Updated Album Title"
},
"Awards": {
"S": "10"
},
"Artist": {
"S": "Acme Band"
},
"SongTitle": {
"S": "Happy Day"
}
}
]
}
```
有关使用 PartiQL 更新数据的更多信息，请参阅 [PartiQL 更新语句](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/ql-reference.update.html)。
------
## Amazon SDK
以下代码示例显示如何使用 Amazon SDK 更新 DynamoDB 表中的项目。
------
#### [ .NET ]
**适用于 .NET 的 Amazon SDK (v4)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/DynamoDB#code-examples)中查找完整示例，了解如何进行设置和运行。
```
///
/// Updates an existing item in the movies table.
///
/// A Movie object containing information for
/// the movie to update.
/// A MovieInfo object that contains the
/// information that will be changed.
/// The name of the table that contains the movie.
/// A Boolean value that indicates the success of the operation.
public async Task UpdateItemAsync(
Movie newMovie,
MovieInfo newInfo,
string tableName)
{
try
{
var key = new Dictionary
{
["title"] = new AttributeValue { S = newMovie.Title },
["year"] = new AttributeValue { N = newMovie.Year.ToString() },
};
var updates = new Dictionary
{
["info.plot"] = new AttributeValueUpdate
{
Action = AttributeAction.PUT,
Value = new AttributeValue { S = newInfo.Plot },
},
["info.rating"] = new AttributeValueUpdate
{
Action = AttributeAction.PUT,
Value = new AttributeValue { N = newInfo.Rank.ToString() },
},
};
var request = new UpdateItemRequest
{
AttributeUpdates = updates,
Key = key,
TableName = tableName,
};
await _amazonDynamoDB.UpdateItemAsync(request);
return true;
}
catch (ResourceNotFoundException ex)
{
Console.WriteLine($"Table {tableName} or item was not found. {ex.Message}");
return false;
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred while updating item. {ex.Message}");
throw;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred while updating item. {ex.Message}");
throw;
}
}
```
+ 有关 API 详细信息，请参阅 *适用于 .NET 的 Amazon SDK API 参考*中的 [UpdateItem](https://docs.amazonaws.cn/goto/DotNetSDKV4/dynamodb-2012-08-10/UpdateItem)。
------
#### [ Bash ]
**Amazon CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
##############################################################################
# function dynamodb_update_item
#
# This function updates an item in a DynamoDB table.
#
#
# Parameters:
# -n table_name -- The name of the table.
# -k keys -- Path to json file containing the keys that identify the item to update.
# -e update expression -- An expression that defines one or more attributes to be updated.
# -v values -- Path to json file containing the update values.
#
# Returns:
# 0 - If successful.
# 1 - If it fails.
#############################################################################
function dynamodb_update_item() {
local table_name keys update_expression values response
local option OPTARG # Required to use getopts command in a function.
#######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_update_item"
echo "Update an item in a DynamoDB table."
echo " -n table_name -- The name of the table."
echo " -k keys -- Path to json file containing the keys that identify the item to update."
echo " -e update expression -- An expression that defines one or more attributes to be updated."
echo " -v values -- Path to json file containing the update values."
echo ""
}
while getopts "n:k:e:v:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
k) keys="${OPTARG}" ;;
e) update_expression="${OPTARG}" ;;
v) values="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
if [[ -z "$keys" ]]; then
errecho "ERROR: You must provide a keys json file path the -k parameter."
usage
return 1
fi
if [[ -z "$update_expression" ]]; then
errecho "ERROR: You must provide an update expression with the -e parameter."
usage
return 1
fi
if [[ -z "$values" ]]; then
errecho "ERROR: You must provide a values json file path the -v parameter."
usage
return 1
fi
iecho "Parameters:\n"
iecho " table_name: $table_name"
iecho " keys: $keys"
iecho " update_expression: $update_expression"
iecho " values: $values"
response=$(aws dynamodb update-item \
--table-name "$table_name" \
--key file://"$keys" \
--update-expression "$update_expression" \
--expression-attribute-values file://"$values")
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports update-item operation failed.$response"
return 1
fi
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function iecho
#
# This function enables the script to display the specified text only if
# the global variable $VERBOSE is set to true.
###############################################################################
function iecho() {
if [[ $VERBOSE == true ]]; then
echo "$@"
fi
}
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《Amazon CLI 命令参考》**中的 [UpdateItem](https://docs.amazonaws.cn/goto/aws-cli/dynamodb-2012-08-10/UpdateItem)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
//! Update an Amazon DynamoDB table item.
/*!
\sa updateItem()
\param tableName: The table name.
\param partitionKey: The partition key.
\param partitionValue: The value for the partition key.
\param attributeKey: The key for the attribute to be updated.
\param attributeValue: The value for the attribute to be updated.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
/*
* The example code only sets/updates an attribute value. It processes
* the attribute value as a string, even if the value could be interpreted
* as a number. Also, the example code does not remove an existing attribute
* from the key value.
*/
bool AwsDoc::DynamoDB::updateItem(const Aws::String &tableName,
const Aws::String &partitionKey,
const Aws::String &partitionValue,
const Aws::String &attributeKey,
const Aws::String &attributeValue,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
// *** Define UpdateItem request arguments.
// Define TableName argument.
Aws::DynamoDB::Model::UpdateItemRequest request;
request.SetTableName(tableName);
// Define KeyName argument.
Aws::DynamoDB::Model::AttributeValue attribValue;
attribValue.SetS(partitionValue);
request.AddKey(partitionKey, attribValue);
// Construct the SET update expression argument.
Aws::String update_expression("SET #a = :valueA");
request.SetUpdateExpression(update_expression);
// Construct attribute name argument.
Aws::Map expressionAttributeNames;
expressionAttributeNames["#a"] = attributeKey;
request.SetExpressionAttributeNames(expressionAttributeNames);
// Construct attribute value argument.
Aws::DynamoDB::Model::AttributeValue attributeUpdatedValue;
attributeUpdatedValue.SetS(attributeValue);
Aws::Map expressionAttributeValues;
expressionAttributeValues[":valueA"] = attributeUpdatedValue;
request.SetExpressionAttributeValues(expressionAttributeValues);
// Update the item.
const Aws::DynamoDB::Model::UpdateItemOutcome &outcome = dynamoClient.UpdateItem(
request);
if (outcome.IsSuccess()) {
std::cout << "Item was updated" << std::endl;
} else {
std::cerr << outcome.GetError().GetMessage() << std::endl;
return false;
}
return waitTableActive(tableName, dynamoClient);
}
```
等待表变为活动状态的代码。
```
//! Query a newly created DynamoDB table until it is active.
/*!
\sa waitTableActive()
\param waitTableActive: The DynamoDB table's name.
\param dynamoClient: A DynamoDB client.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::waitTableActive(const Aws::String &tableName,
const Aws::DynamoDB::DynamoDBClient &dynamoClient) {
// Repeatedly call DescribeTable until table is ACTIVE.
const int MAX_QUERIES = 20;
Aws::DynamoDB::Model::DescribeTableRequest request;
request.SetTableName(tableName);
int count = 0;
while (count < MAX_QUERIES) {
const Aws::DynamoDB::Model::DescribeTableOutcome &result = dynamoClient.DescribeTable(
request);
if (result.IsSuccess()) {
Aws::DynamoDB::Model::TableStatus status = result.GetResult().GetTable().GetTableStatus();
if (Aws::DynamoDB::Model::TableStatus::ACTIVE != status) {
std::this_thread::sleep_for(std::chrono::seconds(1));
}
else {
return true;
}
}
else {
std::cerr << "Error DynamoDB::waitTableActive "
<< result.GetError().GetMessage() << std::endl;
return false;
}
count++;
}
return false;
}
```
+ 有关 API 详细信息，请参阅 *适用于 C\$1\$1 的 Amazon SDK API 参考*中的 [UpdateItem](https://docs.amazonaws.cn/goto/SdkForCpp/dynamodb-2012-08-10/UpdateItem)。
------
#### [ CLI ]
**Amazon CLI**
**示例 1：更新表中的项**
下面的 `update-item` 示例更新 `MusicCollection` 表的项目。它会添加一个新属性（`Year`）并修改 `AlbumTitle` 属性。响应中会返回更新后显示的项中的所有属性。
```
aws dynamodb update-item \
--table-name MusicCollection \
--key file://key.json \
--update-expression "SET #Y = :y, #AT = :t" \
--expression-attribute-names file://expression-attribute-names.json \
--expression-attribute-values file://expression-attribute-values.json \
--return-values ALL_NEW \
--return-consumed-capacity TOTAL \
--return-item-collection-metrics SIZE
```
的内容`key.json`：
```
{
"Artist": {"S": "Acme Band"},
"SongTitle": {"S": "Happy Day"}
}
```
的内容`expression-attribute-names.json`：
```
{
"#Y":"Year", "#AT":"AlbumTitle"
}
```
的内容`expression-attribute-values.json`：
```
{
":y":{"N": "2015"},
":t":{"S": "Louder Than Ever"}
}
```
输出：
```
{
"Attributes": {
"AlbumTitle": {
"S": "Louder Than Ever"
},
"Awards": {
"N": "10"
},
"Artist": {
"S": "Acme Band"
},
"Year": {
"N": "2015"
},
"SongTitle": {
"S": "Happy Day"
}
},
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 3.0
},
"ItemCollectionMetrics": {
"ItemCollectionKey": {
"Artist": {
"S": "Acme Band"
}
},
"SizeEstimateRangeGB": [
0.0,
1.0
]
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[写入项](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.WritingData)。
**示例 2：有条件地更新项**
以下示例将更新 `MusicCollection` 表中的项，但前提是现有项还没有 `Year` 属性。
```
aws dynamodb update-item \
--table-name MusicCollection \
--key file://key.json \
--update-expression "SET #Y = :y, #AT = :t" \
--expression-attribute-names file://expression-attribute-names.json \
--expression-attribute-values file://expression-attribute-values.json \
--condition-expression "attribute_not_exists(#Y)"
```
的内容`key.json`：
```
{
"Artist": {"S": "Acme Band"},
"SongTitle": {"S": "Happy Day"}
}
```
的内容`expression-attribute-names.json`：
```
{
"#Y":"Year",
"#AT":"AlbumTitle"
}
```
的内容`expression-attribute-values.json`：
```
{
":y":{"N": "2015"},
":t":{"S": "Louder Than Ever"}
}
```
如果该项已有 `Year` 属性，DynamoDB 会返回以下输出。
```
An error occurred (ConditionalCheckFailedException) when calling the UpdateItem operation: The conditional request failed
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[写入项](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithItems.html#WorkingWithItems.WritingData)。
+ 有关 API 详细信息，请参阅《Amazon CLI 命令参考》**中的 [UpdateItem](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/update-item.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// UpdateMovie updates the rating and plot of a movie that already exists in the
// DynamoDB table. This function uses the `expression` package to build the update
// expression.
func (basics TableBasics) UpdateMovie(ctx context.Context, movie Movie) (map[string]map[string]interface{}, error) {
var err error
var response *dynamodb.UpdateItemOutput
var attributeMap map[string]map[string]interface{}
update := expression.Set(expression.Name("info.rating"), expression.Value(movie.Info["rating"]))
update.Set(expression.Name("info.plot"), expression.Value(movie.Info["plot"]))
expr, err := expression.NewBuilder().WithUpdate(update).Build()
if err != nil {
log.Printf("Couldn't build expression for update. Here's why: %v\n", err)
} else {
response, err = basics.DynamoDbClient.UpdateItem(ctx, &dynamodb.UpdateItemInput{
TableName: aws.String(basics.TableName),
Key: movie.GetKey(),
ExpressionAttributeNames: expr.Names(),
ExpressionAttributeValues: expr.Values(),
UpdateExpression: expr.Update(),
ReturnValues: types.ReturnValueUpdatedNew,
})
if err != nil {
log.Printf("Couldn't update movie %v. Here's why: %v\n", movie.Title, err)
} else {
err = attributevalue.UnmarshalMap(response.Attributes, &attributeMap)
if err != nil {
log.Printf("Couldn't unmarshall update response. Here's why: %v\n", err)
}
}
}
return attributeMap, err
}
```
定义本示例中使用的 Movie 结构。
```
import (
"archive/zip"
"bytes"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// Movie encapsulates data about a movie. Title and Year are the composite primary key
// of the movie in Amazon DynamoDB. Title is the sort key, Year is the partition key,
// and Info is additional data.
type Movie struct {
Title string `dynamodbav:"title"`
Year int `dynamodbav:"year"`
Info map[string]interface{} `dynamodbav:"info"`
}
// GetKey returns the composite primary key of the movie in a format that can be
// sent to DynamoDB.
func (movie Movie) GetKey() map[string]types.AttributeValue {
title, err := attributevalue.Marshal(movie.Title)
if err != nil {
panic(err)
}
year, err := attributevalue.Marshal(movie.Year)
if err != nil {
panic(err)
}
return map[string]types.AttributeValue{"title": title, "year": year}
}
// String returns the title, year, rating, and plot of a movie, formatted for the example.
func (movie Movie) String() string {
return fmt.Sprintf("%v\n\tReleased: %v\n\tRating: %v\n\tPlot: %v\n",
movie.Title, movie.Year, movie.Info["rating"], movie.Info["plot"])
}
```
+ 有关 API 详细信息，请参阅 *适用于 Go 的 Amazon SDK API 参考*中的 [UpdateItem](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.UpdateItem)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 [DynamoDbClient](https://docs.amazonaws.cn/sdk-for-java/latest/reference/software/amazon/awssdk/services/dynamodb/DynamoDbClient.html) 更新表中的项目。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.AttributeAction;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.AttributeValueUpdate;
import software.amazon.awssdk.services.dynamodb.model.UpdateItemRequest;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import java.util.HashMap;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*
* To update an Amazon DynamoDB table using the AWS SDK for Java V2, its better
* practice to use the
* Enhanced Client, See the EnhancedModifyItem example.
*/
public class UpdateItem {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table (for example, Music3).
key - The name of the key in the table (for example, Artist).
keyVal - The value of the key (for example, Famous Band).
name - The name of the column where the value is updated (for example, Awards).
updateVal - The value used to update an item (for example, 14).
Example:
UpdateItem Music3 Artist Famous Band Awards 14
""";
if (args.length != 5) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
String key = args[1];
String keyVal = args[2];
String name = args[3];
String updateVal = args[4];
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
updateTableItem(ddb, tableName, key, keyVal, name, updateVal);
ddb.close();
}
public static void updateTableItem(DynamoDbClient ddb,
String tableName,
String key,
String keyVal,
String name,
String updateVal) {
HashMap itemKey = new HashMap<>();
itemKey.put(key, AttributeValue.builder()
.s(keyVal)
.build());
HashMap updatedValues = new HashMap<>();
updatedValues.put(name, AttributeValueUpdate.builder()
.value(AttributeValue.builder().s(updateVal).build())
.action(AttributeAction.PUT)
.build());
UpdateItemRequest request = UpdateItemRequest.builder()
.tableName(tableName)
.key(itemKey)
.attributeUpdates(updatedValues)
.build();
try {
ddb.updateItem(request);
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
System.out.println("The Amazon DynamoDB table was updated!");
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Java 2.x API Reference》**中的 [UpdateItem](https://docs.amazonaws.cn/goto/SdkForJavaV2/dynamodb-2012-08-10/UpdateItem)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
此示例使用文档客户端来简化在 DynamoDB 中处理项目的过程。有关 API 详细信息，请参阅 [UpdateCommand](https://docs.amazonaws.cn/AWSJavaScriptSDK/v3/latest/Package/-aws-sdk-lib-dynamodb/Class/UpdateCommand/)。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import { DynamoDBDocumentClient, UpdateCommand } from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new UpdateCommand({
TableName: "Dogs",
Key: {
Breed: "Labrador",
},
UpdateExpression: "set Color = :color",
ExpressionAttributeValues: {
":color": "black",
},
ReturnValues: "ALL_NEW",
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 Amazon SDK API Reference》**中的 [UpdateItem](https://docs.amazonaws.cn/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/UpdateItemCommand)。
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
suspend fun updateTableItem(
tableNameVal: String,
keyName: String,
keyVal: String,
name: String,
updateVal: String,
) {
val itemKey = mutableMapOf()
itemKey[keyName] = AttributeValue.S(keyVal)
val updatedValues = mutableMapOf()
updatedValues[name] =
AttributeValueUpdate {
value = AttributeValue.S(updateVal)
action = AttributeAction.Put
}
val request =
UpdateItemRequest {
tableName = tableNameVal
key = itemKey
attributeUpdates = updatedValues
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
ddb.updateItem(request)
println("Item in $tableNameVal was updated")
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Kotlin API Reference》**中的 [UpdateItem](https://sdk.amazonaws.com/kotlin/api/latest/index.html)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
echo "What rating would you like to give {$movie['Item']['title']['S']}?\n";
$rating = 0;
while (!is_numeric($rating) || intval($rating) != $rating || $rating < 1 || $rating > 10) {
$rating = testable_readline("Rating (1-10): ");
}
$service->updateItemAttributeByKey($tableName, $key, 'rating', 'N', $rating);
public function updateItemAttributeByKey(
string $tableName,
array $key,
string $attributeName,
string $attributeType,
string $newValue
) {
$this->dynamoDbClient->updateItem([
'Key' => $key['Item'],
'TableName' => $tableName,
'UpdateExpression' => "set #NV=:NV",
'ExpressionAttributeNames' => [
'#NV' => $attributeName,
],
'ExpressionAttributeValues' => [
':NV' => [
$attributeType => $newValue
]
],
]);
}
```
+ 有关 API 的详细信息，请参阅 *适用于 PHP 的 Amazon SDK API 参考*中的 [UpdateItem](https://docs.amazonaws.cn/goto/SdkForPHPV3/dynamodb-2012-08-10/UpdateItem)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：在带有分区键 SongTitle 和排序键 Artist 的 DynamoDB 项目上将流派属性设置为“Rap”**。
```
$key = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
} | ConvertTo-DDBItem
$updateDdbItem = @{
TableName = 'Music'
Key = $key
UpdateExpression = 'set Genre = :val1'
ExpressionAttributeValue = (@{
':val1' = ([Amazon.DynamoDBv2.Model.AttributeValue]'Rap')
})
}
Update-DDBItem @updateDdbItem
```
**输出：**
```
Name Value
---- -----
Genre Rap
```
+ 有关 API 详细信息，请参阅《Amazon Tools for PowerShell Cmdlet Reference (V4)》**中的 [UpdateItem](https://docs.amazonaws.cn/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：在带有分区键 SongTitle 和排序键 Artist 的 DynamoDB 项目上将流派属性设置为“Rap”**。
```
$key = @{
SongTitle = 'Somewhere Down The Road'
Artist = 'No One You Know'
} | ConvertTo-DDBItem
$updateDdbItem = @{
TableName = 'Music'
Key = $key
UpdateExpression = 'set Genre = :val1'
ExpressionAttributeValue = (@{
':val1' = ([Amazon.DynamoDBv2.Model.AttributeValue]'Rap')
})
}
Update-DDBItem @updateDdbItem
```
**输出：**
```
Name Value
---- -----
Genre Rap
```
+ 有关 API 详细信息，请参阅《Amazon Tools for PowerShell Cmdlet Reference (V5)》**中的 [UpdateItem](https://docs.amazonaws.cn/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用更新表达式更新项目
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def update_movie(self, title, year, rating, plot):
"""
Updates rating and plot data for a movie in the table.
:param title: The title of the movie to update.
:param year: The release year of the movie to update.
:param rating: The updated rating to the give the movie.
:param plot: The updated plot summary to give the movie.
:return: The fields that were updated, with their new values.
"""
try:
response = self.table.update_item(
Key={"year": year, "title": title},
UpdateExpression="set info.rating=:r, info.plot=:p",
ExpressionAttributeValues={":r": Decimal(str(rating)), ":p": plot},
ReturnValues="UPDATED_NEW",
)
except ClientError as err:
logger.error(
"Couldn't update movie %s in table %s. Here's why: %s: %s",
title,
self.table.name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return response["Attributes"]
```
使用包含算术运算的更新表达式更新项目。
```
class UpdateQueryWrapper:
def __init__(self, table):
self.table = table
def update_rating(self, title, year, rating_change):
"""
Updates the quality rating of a movie in the table by using an arithmetic
operation in the update expression. By specifying an arithmetic operation,
you can adjust a value in a single request, rather than first getting its
value and then setting its new value.
:param title: The title of the movie to update.
:param year: The release year of the movie to update.
:param rating_change: The amount to add to the current rating for the movie.
:return: The updated rating.
"""
try:
response = self.table.update_item(
Key={"year": year, "title": title},
UpdateExpression="set info.rating = info.rating + :val",
ExpressionAttributeValues={":val": Decimal(str(rating_change))},
ReturnValues="UPDATED_NEW",
)
except ClientError as err:
logger.error(
"Couldn't update movie %s in table %s. Here's why: %s: %s",
title,
self.table.name,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return response["Attributes"]
```
只有在项目满足特定条件时才更新项目。
```
class UpdateQueryWrapper:
def __init__(self, table):
self.table = table
def remove_actors(self, title, year, actor_threshold):
"""
Removes an actor from a movie, but only when the number of actors is greater
than a specified threshold. If the movie does not list more than the threshold,
no actors are removed.
:param title: The title of the movie to update.
:param year: The release year of the movie to update.
:param actor_threshold: The threshold of actors to check.
:return: The movie data after the update.
"""
try:
response = self.table.update_item(
Key={"year": year, "title": title},
UpdateExpression="remove info.actors[0]",
ConditionExpression="size(info.actors) > :num",
ExpressionAttributeValues={":num": actor_threshold},
ReturnValues="ALL_NEW",
)
except ClientError as err:
if err.response["Error"]["Code"] == "ConditionalCheckFailedException":
logger.warning(
"Didn't update %s because it has fewer than %s actors.",
title,
actor_threshold + 1,
)
else:
logger.error(
"Couldn't update movie %s. Here's why: %s: %s",
title,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return response["Attributes"]
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Python（Boto3）API Reference》**中的 [UpdateItem](https://docs.amazonaws.cn/goto/boto3/dynamodb-2012-08-10/UpdateItem)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class DynamoDBBasics
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamo_resource.table(table_name)
end
# Updates rating and plot data for a movie in the table.
#
# @param movie [Hash] The title, year, plot, rating of the movie.
def update_item(movie)
response = @table.update_item(
key: { 'year' => movie[:year], 'title' => movie[:title] },
update_expression: 'set info.rating=:r',
expression_attribute_values: { ':r' => movie[:rating] },
return_values: 'UPDATED_NEW'
)
rescue Aws::DynamoDB::Errors::ServiceError => e
puts("Couldn't update movie #{movie[:title]} (#{movie[:year]}) in table #{@table.name}\n")
puts("\t#{e.code}: #{e.message}")
raise
else
response.attributes
end
```
+ 有关 API 详细信息，请参阅 *适用于 Ruby 的 Amazon SDK API 参考*中的 [UpdateItem](https://docs.amazonaws.cn/goto/SdkForRubyV3/dynamodb-2012-08-10/UpdateItem)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
oo_output = lo_dyn->updateitem(
iv_tablename = iv_table_name
it_key = it_item_key
it_attributeupdates = it_attribute_updates ).
MESSAGE '1 item updated in DynamoDB Table' && iv_table_name TYPE 'I'.
CATCH /aws1/cx_dyncondalcheckfaile00.
MESSAGE 'A condition specified in the operation could not be evaluated.' TYPE 'E'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
CATCH /aws1/cx_dyntransactconflictex.
MESSAGE 'Another transaction is using the item' TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《Amazon SDK for SAP ABAP API Reference》**中的 [UpdateItem](https://docs.amazonaws.cn/sdk-for-sap-abap/v1/api/latest/index.html)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
/// Update the specified movie with new `rating` and `plot` information.
///
/// - Parameters:
/// - title: The title of the movie to update.
/// - year: The release year of the movie to update.
/// - rating: The new rating for the movie.
/// - plot: The new plot summary string for the movie.
///
/// - Returns: An array of mappings of attribute names to their new
/// listing each item actually changed. Items that didn't need to change
/// aren't included in this list. `nil` if no changes were made.
///
func update(title: String, year: Int, rating: Double? = nil, plot: String? = nil) async throws
-> [Swift.String: DynamoDBClientTypes.AttributeValue]?
{
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
// Build the update expression and the list of expression attribute
// values. Include only the information that's changed.
var expressionParts: [String] = []
var attrValues: [Swift.String: DynamoDBClientTypes.AttributeValue] = [:]
if rating != nil {
expressionParts.append("info.rating=:r")
attrValues[":r"] = .n(String(rating!))
}
if plot != nil {
expressionParts.append("info.plot=:p")
attrValues[":p"] = .s(plot!)
}
let expression = "set \(expressionParts.joined(separator: ", "))"
let input = UpdateItemInput(
// Create substitution tokens for the attribute values, to ensure
// no conflicts in expression syntax.
expressionAttributeValues: attrValues,
// The key identifying the movie to update consists of the release
// year and title.
key: [
"year": .n(String(year)),
"title": .s(title)
],
returnValues: .updatedNew,
tableName: self.tableName,
updateExpression: expression
)
let output = try await client.updateItem(input: input)
guard let attributes: [Swift.String: DynamoDBClientTypes.AttributeValue] = output.attributes else {
throw MoviesError.InvalidAttributes
}
return attributes
} catch {
print("ERROR: update:", dump(error))
throw error
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Swift API 参考》**中的 [UpdateItem](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/updateitem(input:))。
------
有关更多 DynamoDB 示例，请参阅[适用于使用 Amazon SDK 的 DynamoDB 的代码示例](service_code_examples.md)。
要查询 `Music` 表的数据，继续 [第 5 步：查询 DynamoDB 表中的数据](getting-started-step-5.md)。
# 第 5 步：查询 DynamoDB 表中的数据
在此步骤中，通过指定 `Artist` 查询写入到 [第 2 步：将数据写入 DynamoDB 表](getting-started-step-2.md) 的 `Music` 表的数据。这将显示与分区键关联的所有歌曲：`Artist`。
有关写入操作的更多信息，请参阅 [在 DynamoDB 中查询表](Query.md)。
## Amazon Web Services 管理控制台
按照这些步骤使用 DynamoDB 控制台查询 `Music` 表中的数据。
1. 打开 DynamoDB 控制台：[https://console.aws.amazon.com/dynamodb/](https://console.amazonaws.cn/dynamodb/)。
1. 在左侧导航窗格中，选择 **表**。
1. 从表列表中选择 **Music** 表。
1. 选择**浏览表项目**。
1. 在**扫描或查询项目**中，确保已选择**查询**。
1. 对于 **Partition key (分区键)**，输入 **Acme Band**，然后选择 **Run (运行)**。
## Amazon CLI
下面的 Amazon CLI 示例将查询 `Music` 表中的项目。您可以通过 DynamoDB API 或 [PartiQL](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/ql-reference.html)（一种适用于 DynamoDB 的 SQL 兼容查询语言）执行此操作。
------
#### [ DynamoDB API ]
您可以使用 `query` 并提供分区键来通过 DynamoDB API 查询项目。
**Linux**
```
aws dynamodb query \
--table-name Music \
--key-condition-expression "Artist = :name" \
--expression-attribute-values '{":name":{"S":"Acme Band"}}'
```
**Windows CMD**
```
aws dynamodb query ^
--table-name Music ^
--key-condition-expression "Artist = :name" ^
--expression-attribute-values "{\":name\":{\"S\":\"Acme Band\"}}"
```
使用 `query` 将返回与此特定 `Artist` 关联的所有歌曲。
```
{
"Items": [
{
"AlbumTitle": {
"S": "Updated Album Title"
},
"Awards": {
"N": "10"
},
"Artist": {
"S": "Acme Band"
},
"SongTitle": {
"S": "Happy Day"
}
},
{
"AlbumTitle": {
"S": "Another Album Title"
},
"Awards": {
"N": "8"
},
"Artist": {
"S": "Acme Band"
},
"SongTitle": {
"S": "PartiQL Rocks"
}
}
],
"Count": 2,
"ScannedCount": 2,
"ConsumedCapacity": null
}
```
------
#### [ PartiQL for DynamoDB ]
您可以使用 `Select` 语句并提供分区键来通过 PartiQL 查询项目。
**Linux**
```
aws dynamodb execute-statement --statement "SELECT * FROM Music \
WHERE Artist='Acme Band'"
```
**Windows CMD**
```
aws dynamodb execute-statement --statement "SELECT * FROM Music WHERE Artist='Acme Band'"
```
通过此方式使用 `Select` 语句将返回与此特定 `Artist` 关联的所有歌曲。
```
{
"Items": [
{
"AlbumTitle": {
"S": "Updated Album Title"
},
"Awards": {
"S": "10"
},
"Artist": {
"S": "Acme Band"
},
"SongTitle": {
"S": "Happy Day"
}
},
{
"AlbumTitle": {
"S": "Another Album Title"
},
"Awards": {
"S": "8"
},
"Artist": {
"S": "Acme Band"
},
"SongTitle": {
"S": "PartiQL Rocks"
}
}
]
}
```
有关使用 PartiQL 查询数据的更多信息，请参阅 [PartiQL 选择语句](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/ql-reference.select.html)。
------
## Amazon SDK
以下代码示例显示如何使用 Amazon SDK 查询 DynamoDB 表。
------
#### [ .NET ]
**适用于 .NET 的 Amazon SDK (v4)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/DynamoDB#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
///
/// Queries the table for movies released in a particular year and
/// then displays the information for the movies returned.
///
/// The name of the table to query.
/// The release year for which we want to
/// view movies.
/// The number of movies that match the query.
public async Task QueryMoviesAsync(string tableName, int year)
{
try
{
var movieTable = new TableBuilder(_amazonDynamoDB, tableName)
.AddHashKey("year", DynamoDBEntryType.Numeric)
.AddRangeKey("title", DynamoDBEntryType.String)
.Build();
var filter = new QueryFilter("year", QueryOperator.Equal, year);
Console.WriteLine("\nFind movies released in: {year}:");
var config = new QueryOperationConfig()
{
Limit = 10, // 10 items per page.
Select = SelectValues.SpecificAttributes,
AttributesToGet = new List
{
"title",
"year",
},
ConsistentRead = true,
Filter = filter,
};
// Value used to track how many movies match the
// supplied criteria.
var moviesFound = 0;
var search = movieTable.Query(config);
do
{
var movieList = await search.GetNextSetAsync();
moviesFound += movieList.Count;
foreach (var movie in movieList)
{
DisplayDocument(movie);
}
}
while (!search.IsDone);
return moviesFound;
}
catch (ResourceNotFoundException ex)
{
Console.WriteLine($"Table {tableName} was not found. {ex.Message}");
return 0;
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred while querying movies. {ex.Message}");
throw;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred while querying movies. {ex.Message}");
throw;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 Amazon SDK API Reference》**中的 [Query](https://docs.amazonaws.cn/goto/DotNetSDKV4/dynamodb-2012-08-10/Query)。
------
#### [ Bash ]
**Amazon CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
#############################################################################
# function dynamodb_query
#
# This function queries a DynamoDB table.
#
# Parameters:
# -n table_name -- The name of the table.
# -k key_condition_expression -- The key condition expression.
# -a attribute_names -- Path to JSON file containing the attribute names.
# -v attribute_values -- Path to JSON file containing the attribute values.
# [-p projection_expression] -- Optional projection expression.
#
# Returns:
# The items as json output.
# And:
# 0 - If successful.
# 1 - If it fails.
###########################################################################
function dynamodb_query() {
local table_name key_condition_expression attribute_names attribute_values projection_expression response
local option OPTARG # Required to use getopts command in a function.
# ######################################
# Function usage explanation
#######################################
function usage() {
echo "function dynamodb_query"
echo "Query a DynamoDB table."
echo " -n table_name -- The name of the table."
echo " -k key_condition_expression -- The key condition expression."
echo " -a attribute_names -- Path to JSON file containing the attribute names."
echo " -v attribute_values -- Path to JSON file containing the attribute values."
echo " [-p projection_expression] -- Optional projection expression."
echo ""
}
while getopts "n:k:a:v:p:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
k) key_condition_expression="${OPTARG}" ;;
a) attribute_names="${OPTARG}" ;;
v) attribute_values="${OPTARG}" ;;
p) projection_expression="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
if [[ -z "$key_condition_expression" ]]; then
errecho "ERROR: You must provide a key condition expression with the -k parameter."
usage
return 1
fi
if [[ -z "$attribute_names" ]]; then
errecho "ERROR: You must provide a attribute names with the -a parameter."
usage
return 1
fi
if [[ -z "$attribute_values" ]]; then
errecho "ERROR: You must provide a attribute values with the -v parameter."
usage
return 1
fi
if [[ -z "$projection_expression" ]]; then
response=$(aws dynamodb query \
--table-name "$table_name" \
--key-condition-expression "$key_condition_expression" \
--expression-attribute-names file://"$attribute_names" \
--expression-attribute-values file://"$attribute_values")
else
response=$(aws dynamodb query \
--table-name "$table_name" \
--key-condition-expression "$key_condition_expression" \
--expression-attribute-names file://"$attribute_names" \
--expression-attribute-values file://"$attribute_values" \
--projection-expression "$projection_expression")
fi
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports query operation failed.$response"
return 1
fi
echo "$response"
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《Amazon CLI 命令参考》**中的 [Query](https://docs.amazonaws.cn/goto/aws-cli/dynamodb-2012-08-10/Query)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
//! Perform a query on an Amazon DynamoDB Table and retrieve items.
/*!
\sa queryItem()
\param tableName: The table name.
\param partitionKey: The partition key.
\param partitionValue: The value for the partition key.
\param projectionExpression: The projections expression, which is ignored if empty.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
/*
* The partition key attribute is searched with the specified value. By default, all fields and values
* contained in the item are returned. If an optional projection expression is
* specified on the command line, only the specified fields and values are
* returned.
*/
bool AwsDoc::DynamoDB::queryItems(const Aws::String &tableName,
const Aws::String &partitionKey,
const Aws::String &partitionValue,
const Aws::String &projectionExpression,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::QueryRequest request;
request.SetTableName(tableName);
if (!projectionExpression.empty()) {
request.SetProjectionExpression(projectionExpression);
}
// Set query key condition expression.
request.SetKeyConditionExpression(partitionKey + "= :valueToMatch");
// Set Expression AttributeValues.
Aws::Map attributeValues;
attributeValues.emplace(":valueToMatch", partitionValue);
request.SetExpressionAttributeValues(attributeValues);
bool result = true;
// "exclusiveStartKey" is used for pagination.
Aws::Map exclusiveStartKey;
do {
if (!exclusiveStartKey.empty()) {
request.SetExclusiveStartKey(exclusiveStartKey);
exclusiveStartKey.clear();
}
// Perform Query operation.
const Aws::DynamoDB::Model::QueryOutcome &outcome = dynamoClient.Query(request);
if (outcome.IsSuccess()) {
// Reference the retrieved items.
const Aws::Vector> &items = outcome.GetResult().GetItems();
if (!items.empty()) {
std::cout << "Number of items retrieved from Query: " << items.size()
<< std::endl;
// Iterate each item and print.
for (const auto &item: items) {
std::cout
<< "******************************************************"
<< std::endl;
// Output each retrieved field and its value.
for (const auto &i: item)
std::cout << i.first << ": " << i.second.GetS() << std::endl;
}
}
else {
std::cout << "No item found in table: " << tableName << std::endl;
}
exclusiveStartKey = outcome.GetResult().GetLastEvaluatedKey();
}
else {
std::cerr << "Failed to Query items: " << outcome.GetError().GetMessage();
result = false;
break;
}
} while (!exclusiveStartKey.empty());
return result;
}
```
+ 有关 API 详细信息，请参阅 *适用于 C\$1\$1 的 Amazon SDK API 参考*中的 [Query](https://docs.amazonaws.cn/goto/SdkForCpp/dynamodb-2012-08-10/Query)。
------
#### [ CLI ]
**Amazon CLI**
**示例 1：查询表**
以下 `query` 示例查询 `MusicCollection` 表中的项。该表具有 hash-and-range 主键（`Artist` 和 `SongTitle`），但此查询仅指定哈希键值。它返回名为“No One You Know”的艺术家的歌名。
```
aws dynamodb query \
--table-name MusicCollection \
--projection-expression "SongTitle" \
--key-condition-expression "Artist = :v1" \
--expression-attribute-values file://expression-attributes.json \
--return-consumed-capacity TOTAL
```
的内容`expression-attributes.json`：
```
{
":v1": {"S": "No One You Know"}
}
```
输出：
```
{
"Items": [
{
"SongTitle": {
"S": "Call Me Today"
},
"SongTitle": {
"S": "Scared of My Shadow"
}
}
],
"Count": 2,
"ScannedCount": 2,
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 0.5
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[使用 DynamoDB 中的查询](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/Query.html)。
**示例 2：使用强一致性读取查询表并按降序遍历索引**
以下示例执行与第一个示例相同的查询，但返回结果的顺序相反，并且使用强一致性读取。
```
aws dynamodb query \
--table-name MusicCollection \
--projection-expression "SongTitle" \
--key-condition-expression "Artist = :v1" \
--expression-attribute-values file://expression-attributes.json \
--consistent-read \
--no-scan-index-forward \
--return-consumed-capacity TOTAL
```
的内容`expression-attributes.json`：
```
{
":v1": {"S": "No One You Know"}
}
```
输出：
```
{
"Items": [
{
"SongTitle": {
"S": "Scared of My Shadow"
}
},
{
"SongTitle": {
"S": "Call Me Today"
}
}
],
"Count": 2,
"ScannedCount": 2,
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 1.0
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[使用 DynamoDB 中的查询](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/Query.html)。
**示例 3：筛选出特定结果**
以下示例查询 `MusicCollection`，但不包括 `AlbumTitle` 属性中含特定值的结果。请注意，这不会影响 `ScannedCount` 或 `ConsumedCapacity`，因为筛选器在读取项之后应用。
```
aws dynamodb query \
--table-name MusicCollection \
--key-condition-expression "#n1 = :v1" \
--filter-expression "NOT (#n2 IN (:v2, :v3))" \
--expression-attribute-names file://names.json \
--expression-attribute-values file://values.json \
--return-consumed-capacity TOTAL
```
的内容`values.json`：
```
{
":v1": {"S": "No One You Know"},
":v2": {"S": "Blue Sky Blues"},
":v3": {"S": "Greatest Hits"}
}
```
的内容`names.json`：
```
{
"#n1": "Artist",
"#n2": "AlbumTitle"
}
```
输出：
```
{
"Items": [
{
"AlbumTitle": {
"S": "Somewhat Famous"
},
"Artist": {
"S": "No One You Know"
},
"SongTitle": {
"S": "Call Me Today"
}
}
],
"Count": 1,
"ScannedCount": 2,
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 0.5
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[使用 DynamoDB 中的查询](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/Query.html)。
**示例 4：仅检索项计数**
以下示例检索与查询匹配的项计数，但不检索任何项本身。
```
aws dynamodb query \
--table-name MusicCollection \
--select COUNT \
--key-condition-expression "Artist = :v1" \
--expression-attribute-values file://expression-attributes.json
```
的内容`expression-attributes.json`：
```
{
":v1": {"S": "No One You Know"}
}
```
输出：
```
{
"Count": 2,
"ScannedCount": 2,
"ConsumedCapacity": null
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[使用 DynamoDB 中的查询](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/Query.html)。
**示例 5：查询索引**
以下示例查询本地二级索引 `AlbumTitleIndex`。该查询返回基表中已投影到本地二级索引的所有属性。请注意，查询本地二级索引或全局二级索引时，您还必须使用 `table-name` 参数提供基表的名称。
```
aws dynamodb query \
--table-name MusicCollection \
--index-name AlbumTitleIndex \
--key-condition-expression "Artist = :v1" \
--expression-attribute-values file://expression-attributes.json \
--select ALL_PROJECTED_ATTRIBUTES \
--return-consumed-capacity INDEXES
```
的内容`expression-attributes.json`：
```
{
":v1": {"S": "No One You Know"}
}
```
输出：
```
{
"Items": [
{
"AlbumTitle": {
"S": "Blue Sky Blues"
},
"Artist": {
"S": "No One You Know"
},
"SongTitle": {
"S": "Scared of My Shadow"
}
},
{
"AlbumTitle": {
"S": "Somewhat Famous"
},
"Artist": {
"S": "No One You Know"
},
"SongTitle": {
"S": "Call Me Today"
}
}
],
"Count": 2,
"ScannedCount": 2,
"ConsumedCapacity": {
"TableName": "MusicCollection",
"CapacityUnits": 0.5,
"Table": {
"CapacityUnits": 0.0
},
"LocalSecondaryIndexes": {
"AlbumTitleIndex": {
"CapacityUnits": 0.5
}
}
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[使用 DynamoDB 中的查询](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/Query.html)。
+ 有关 API 详细信息，请参阅《Amazon CLI 命令参考》**中的 [Query](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/query.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// Query gets all movies in the DynamoDB table that were released in the specified year.
// The function uses the `expression` package to build the key condition expression
// that is used in the query.
func (basics TableBasics) Query(ctx context.Context, releaseYear int) ([]Movie, error) {
var err error
var response *dynamodb.QueryOutput
var movies []Movie
keyEx := expression.Key("year").Equal(expression.Value(releaseYear))
expr, err := expression.NewBuilder().WithKeyCondition(keyEx).Build()
if err != nil {
log.Printf("Couldn't build expression for query. Here's why: %v\n", err)
} else {
queryPaginator := dynamodb.NewQueryPaginator(basics.DynamoDbClient, &dynamodb.QueryInput{
TableName: aws.String(basics.TableName),
ExpressionAttributeNames: expr.Names(),
ExpressionAttributeValues: expr.Values(),
KeyConditionExpression: expr.KeyCondition(),
})
for queryPaginator.HasMorePages() {
response, err = queryPaginator.NextPage(ctx)
if err != nil {
log.Printf("Couldn't query for movies released in %v. Here's why: %v\n", releaseYear, err)
break
} else {
var moviePage []Movie
err = attributevalue.UnmarshalListOfMaps(response.Items, &moviePage)
if err != nil {
log.Printf("Couldn't unmarshal query response. Here's why: %v\n", err)
break
} else {
movies = append(movies, moviePage...)
}
}
}
}
return movies, err
}
```
定义本示例中使用的 Movie 结构。
```
import (
"archive/zip"
"bytes"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// Movie encapsulates data about a movie. Title and Year are the composite primary key
// of the movie in Amazon DynamoDB. Title is the sort key, Year is the partition key,
// and Info is additional data.
type Movie struct {
Title string `dynamodbav:"title"`
Year int `dynamodbav:"year"`
Info map[string]interface{} `dynamodbav:"info"`
}
// GetKey returns the composite primary key of the movie in a format that can be
// sent to DynamoDB.
func (movie Movie) GetKey() map[string]types.AttributeValue {
title, err := attributevalue.Marshal(movie.Title)
if err != nil {
panic(err)
}
year, err := attributevalue.Marshal(movie.Year)
if err != nil {
panic(err)
}
return map[string]types.AttributeValue{"title": title, "year": year}
}
// String returns the title, year, rating, and plot of a movie, formatted for the example.
func (movie Movie) String() string {
return fmt.Sprintf("%v\n\tReleased: %v\n\tRating: %v\n\tPlot: %v\n",
movie.Title, movie.Year, movie.Info["rating"], movie.Info["plot"])
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 Amazon SDK API Reference》**中的 [Query](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.Query)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用 [DynamoDbClient](https://docs.amazonaws.cn/sdk-for-java/latest/reference/software/amazon/awssdk/services/dynamodb/DynamoDbClient.html) 查询表。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.QueryRequest;
import software.amazon.awssdk.services.dynamodb.model.QueryResponse;
import java.util.HashMap;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*
* To query items from an Amazon DynamoDB table using the AWS SDK for Java V2,
* its better practice to use the
* Enhanced Client. See the EnhancedQueryRecords example.
*/
public class Query {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table to put the item in (for example, Music3).
partitionKeyName - The partition key name of the Amazon DynamoDB table (for example, Artist).
partitionKeyVal - The value of the partition key that should match (for example, Famous Band).
""";
if (args.length != 3) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
String partitionKeyName = args[1];
String partitionKeyVal = args[2];
// For more information about an alias, see:
// https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.ExpressionAttributeNames.html
String partitionAlias = "#a";
System.out.format("Querying %s", tableName);
System.out.println("");
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
int count = queryTable(ddb, tableName, partitionKeyName, partitionKeyVal, partitionAlias);
System.out.println("There were " + count + " record(s) returned");
ddb.close();
}
public static int queryTable(DynamoDbClient ddb, String tableName, String partitionKeyName, String partitionKeyVal,
String partitionAlias) {
// Set up an alias for the partition key name in case it's a reserved word.
HashMap attrNameAlias = new HashMap();
attrNameAlias.put(partitionAlias, partitionKeyName);
// Set up mapping of the partition name with the value.
HashMap attrValues = new HashMap<>();
attrValues.put(":" + partitionKeyName, AttributeValue.builder()
.s(partitionKeyVal)
.build());
QueryRequest queryReq = QueryRequest.builder()
.tableName(tableName)
.keyConditionExpression(partitionAlias + " = :" + partitionKeyName)
.expressionAttributeNames(attrNameAlias)
.expressionAttributeValues(attrValues)
.build();
try {
QueryResponse response = ddb.query(queryReq);
return response.count();
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
return -1;
}
}
```
使用 `DynamoDbClient` 和二级索引查询表。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.model.QueryRequest;
import software.amazon.awssdk.services.dynamodb.model.QueryResponse;
import java.util.HashMap;
import java.util.Map;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*
* Create the Movies table by running the Scenario example and loading the Movie
* data from the JSON file. Next create a secondary
* index for the Movies table that uses only the year column. Name the index
* **year-index**. For more information, see:
*
* https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/GSI.html
*/
public class QueryItemsUsingIndex {
public static void main(String[] args) {
String tableName = "Movies";
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
queryIndex(ddb, tableName);
ddb.close();
}
public static void queryIndex(DynamoDbClient ddb, String tableName) {
try {
Map expressionAttributesNames = new HashMap<>();
expressionAttributesNames.put("#year", "year");
Map expressionAttributeValues = new HashMap<>();
expressionAttributeValues.put(":yearValue", AttributeValue.builder().n("2013").build());
QueryRequest request = QueryRequest.builder()
.tableName(tableName)
.indexName("year-index")
.keyConditionExpression("#year = :yearValue")
.expressionAttributeNames(expressionAttributesNames)
.expressionAttributeValues(expressionAttributeValues)
.build();
System.out.println("=== Movie Titles ===");
QueryResponse response = ddb.query(request);
response.items()
.forEach(movie -> System.out.println(movie.get("title").s()));
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Java 2.x API Reference》**中的 [Query](https://docs.amazonaws.cn/goto/SdkForJavaV2/dynamodb-2012-08-10/Query)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
此示例使用文档客户端来简化在 DynamoDB 中处理项目的过程。有关 API 详细信息，请参阅 [QueryCommand](https://docs.amazonaws.cn/AWSJavaScriptSDK/v3/latest/Package/-aws-sdk-lib-dynamodb/Class/QueryCommand/)。
```
import { DynamoDBClient } from "@aws-sdk/client-dynamodb";
import { QueryCommand, DynamoDBDocumentClient } from "@aws-sdk/lib-dynamodb";
const client = new DynamoDBClient({});
const docClient = DynamoDBDocumentClient.from(client);
export const main = async () => {
const command = new QueryCommand({
TableName: "CoffeeCrop",
KeyConditionExpression:
"OriginCountry = :originCountry AND RoastDate > :roastDate",
ExpressionAttributeValues: {
":originCountry": "Ethiopia",
":roastDate": "2023-05-01",
},
ConsistentRead: true,
});
const response = await docClient.send(command);
console.log(response);
return response;
};
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 Amazon SDK 开发人员指南》[https://docs.amazonaws.cn/sdk-for-javascript/v3/developer-guide/dynamodb-example-query-scan.html#dynamodb-example-table-query-scan-querying](https://docs.amazonaws.cn/sdk-for-javascript/v3/developer-guide/dynamodb-example-query-scan.html#dynamodb-example-table-query-scan-querying)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 Amazon SDK API Reference》**中的 [Query](https://docs.amazonaws.cn/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/QueryCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create DynamoDB document client
var docClient = new AWS.DynamoDB.DocumentClient({ apiVersion: "2012-08-10" });
var params = {
ExpressionAttributeValues: {
":s": 2,
":e": 9,
":topic": "PHRASE",
},
KeyConditionExpression: "Season = :s and Episode > :e",
FilterExpression: "contains (Subtitle, :topic)",
TableName: "EPISODES_TABLE",
};
docClient.query(params, function (err, data) {
if (err) {
console.log("Error", err);
} else {
console.log("Success", data.Items);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 Amazon SDK 开发人员指南》[https://docs.amazonaws.cn/sdk-for-javascript/v2/developer-guide/dynamodb-example-query-scan.html#dynamodb-example-table-query-scan-querying](https://docs.amazonaws.cn/sdk-for-javascript/v2/developer-guide/dynamodb-example-query-scan.html#dynamodb-example-table-query-scan-querying)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 Amazon SDK API Reference》**中的 [Query](https://docs.amazonaws.cn/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/Query)。
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
suspend fun queryDynTable(
tableNameVal: String,
partitionKeyName: String,
partitionKeyVal: String,
partitionAlias: String,
): Int {
val attrNameAlias = mutableMapOf()
attrNameAlias[partitionAlias] = partitionKeyName
// Set up mapping of the partition name with the value.
val attrValues = mutableMapOf()
attrValues[":$partitionKeyName"] = AttributeValue.S(partitionKeyVal)
val request =
QueryRequest {
tableName = tableNameVal
keyConditionExpression = "$partitionAlias = :$partitionKeyName"
expressionAttributeNames = attrNameAlias
this.expressionAttributeValues = attrValues
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
val response = ddb.query(request)
return response.count
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Kotlin API Reference》**中的 [Query](https://sdk.amazonaws.com/kotlin/api/latest/index.html)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
$birthKey = [
'Key' => [
'year' => [
'N' => "$birthYear",
],
],
];
$result = $service->query($tableName, $birthKey);
public function query(string $tableName, $key)
{
$expressionAttributeValues = [];
$expressionAttributeNames = [];
$keyConditionExpression = "";
$index = 1;
foreach ($key as $name => $value) {
$keyConditionExpression .= "#" . array_key_first($value) . " = :v$index,";
$expressionAttributeNames["#" . array_key_first($value)] = array_key_first($value);
$hold = array_pop($value);
$expressionAttributeValues[":v$index"] = [
array_key_first($hold) => array_pop($hold),
];
}
$keyConditionExpression = substr($keyConditionExpression, 0, -1);
$query = [
'ExpressionAttributeValues' => $expressionAttributeValues,
'ExpressionAttributeNames' => $expressionAttributeNames,
'KeyConditionExpression' => $keyConditionExpression,
'TableName' => $tableName,
];
return $this->dynamoDbClient->query($query);
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 Amazon SDK API Reference》**中的 [Query](https://docs.amazonaws.cn/goto/SdkForPHPV3/dynamodb-2012-08-10/Query)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：调用一个查询，该查询返回具有指定 SongTitle 和 Artist 的 DynamoDB 项目。**
```
$invokeDDBQuery = @{
TableName = 'Music'
KeyConditionExpression = ' SongTitle = :SongTitle and Artist = :Artist'
ExpressionAttributeValues = @{
':SongTitle' = 'Somewhere Down The Road'
':Artist' = 'No One You Know'
} | ConvertTo-DDBItem
}
Invoke-DDBQuery @invokeDDBQuery | ConvertFrom-DDBItem
```
**输出：**
```
Name Value
---- -----
Genre Country
Artist No One You Know
Price 1.94
CriticRating 9
SongTitle Somewhere Down The Road
AlbumTitle Somewhat Famous
```
+ 有关 API 详细信息，请参阅《Amazon Tools for PowerShell Cmdlet Reference (V4)》**中的 [Query](https://docs.amazonaws.cn/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：调用一个查询，该查询返回具有指定 SongTitle 和 Artist 的 DynamoDB 项目。**
```
$invokeDDBQuery = @{
TableName = 'Music'
KeyConditionExpression = ' SongTitle = :SongTitle and Artist = :Artist'
ExpressionAttributeValues = @{
':SongTitle' = 'Somewhere Down The Road'
':Artist' = 'No One You Know'
} | ConvertTo-DDBItem
}
Invoke-DDBQuery @invokeDDBQuery | ConvertFrom-DDBItem
```
**输出：**
```
Name Value
---- -----
Genre Country
Artist No One You Know
Price 1.94
CriticRating 9
SongTitle Somewhere Down The Road
AlbumTitle Somewhat Famous
```
+ 有关 API 详细信息，请参阅《Amazon Tools for PowerShell Cmdlet Reference (V5)》**中的 [Query](https://docs.amazonaws.cn/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
使用关键条件表达式查询项目。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def query_movies(self, year):
"""
Queries for movies that were released in the specified year.
:param year: The year to query.
:return: The list of movies that were released in the specified year.
"""
try:
response = self.table.query(KeyConditionExpression=Key("year").eq(year))
except ClientError as err:
logger.error(
"Couldn't query for movies released in %s. Here's why: %s: %s",
year,
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return response["Items"]
```
查询项目并将其投影以返回数据的子集。
```
class UpdateQueryWrapper:
def __init__(self, table):
self.table = table
def query_and_project_movies(self, year, title_bounds):
"""
Query for movies that were released in a specified year and that have titles
that start within a range of letters. A projection expression is used
to return a subset of data for each movie.
:param year: The release year to query.
:param title_bounds: The range of starting letters to query.
:return: The list of movies.
"""
try:
response = self.table.query(
ProjectionExpression="#yr, title, info.genres, info.actors[0]",
ExpressionAttributeNames={"#yr": "year"},
KeyConditionExpression=(
Key("year").eq(year)
& Key("title").between(
title_bounds["first"], title_bounds["second"]
)
),
)
except ClientError as err:
if err.response["Error"]["Code"] == "ValidationException":
logger.warning(
"There's a validation error. Here's the message: %s: %s",
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
else:
logger.error(
"Couldn't query for movies. Here's why: %s: %s",
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
else:
return response["Items"]
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Python (Boto3) API Reference》**中的 [Query](https://docs.amazonaws.cn/goto/boto3/dynamodb-2012-08-10/Query)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
class DynamoDBBasics
attr_reader :dynamo_resource, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table = @dynamo_resource.table(table_name)
end
# Queries for movies that were released in the specified year.
#
# @param year [Integer] The year to query.
# @return [Array] The list of movies that were released in the specified year.
def query_items(year)
response = @table.query(
key_condition_expression: '#yr = :year',
expression_attribute_names: { '#yr' => 'year' },
expression_attribute_values: { ':year' => year }
)
rescue Aws::DynamoDB::Errors::ServiceError => e
puts("Couldn't query for movies released in #{year}. Here's why:")
puts("\t#{e.code}: #{e.message}")
raise
else
response.items
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 Amazon SDK API Reference》**中的 [Query](https://docs.amazonaws.cn/goto/SdkForRubyV3/dynamodb-2012-08-10/Query)。
------
#### [ Rust ]
**适用于 Rust 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
查找指定年份制作的电影。
```
pub async fn movies_in_year(
client: &Client,
table_name: &str,
year: u16,
) -> Result, MovieError> {
let results = client
.query()
.table_name(table_name)
.key_condition_expression("#yr = :yyyy")
.expression_attribute_names("#yr", "year")
.expression_attribute_values(":yyyy", AttributeValue::N(year.to_string()))
.send()
.await?;
if let Some(items) = results.items {
let movies = items.iter().map(|v| v.into()).collect();
Ok(movies)
} else {
Ok(vec![])
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Rust API Reference》**中的 [Query](https://docs.rs/aws-sdk-dynamodb/latest/aws_sdk_dynamodb/client/struct.Client.html#method.query)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
" Query movies for a given year .
DATA(lt_attributelist) = VALUE /aws1/cl_dynattributevalue=>tt_attributevaluelist(
( NEW /aws1/cl_dynattributevalue( iv_n = |{ iv_year }| ) ) ).
DATA(lt_key_conditions) = VALUE /aws1/cl_dyncondition=>tt_keyconditions(
( VALUE /aws1/cl_dyncondition=>ts_keyconditions_maprow(
key = 'year'
value = NEW /aws1/cl_dyncondition(
it_attributevaluelist = lt_attributelist
iv_comparisonoperator = |EQ|
) ) ) ).
oo_result = lo_dyn->query(
iv_tablename = iv_table_name
it_keyconditions = lt_key_conditions ).
DATA(lt_items) = oo_result->get_items( ).
"You can loop over the results to get item attributes.
LOOP AT lt_items INTO DATA(lt_item).
DATA(lo_title) = lt_item[ key = 'title' ]-value.
DATA(lo_year) = lt_item[ key = 'year' ]-value.
ENDLOOP.
DATA(lv_count) = oo_result->get_count( ).
MESSAGE 'Item count is: ' && lv_count TYPE 'I'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table or index does not exist' TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《Amazon SDK for SAP ABAP API Reference》**中的 [Query](https://docs.amazonaws.cn/sdk-for-sap-abap/v1/api/latest/index.html)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
/// Get all the movies released in the specified year.
///
/// - Parameter year: The release year of the movies to return.
///
/// - Returns: An array of `Movie` objects describing each matching movie.
///
func getMovies(fromYear year: Int) async throws -> [Movie] {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = QueryInput(
expressionAttributeNames: [
"#y": "year"
],
expressionAttributeValues: [
":y": .n(String(year))
],
keyConditionExpression: "#y = :y",
tableName: self.tableName
)
// Use "Paginated" to get all the movies.
// This lets the SDK handle the 'lastEvaluatedKey' property in "QueryOutput".
let pages = client.queryPaginated(input: input)
var movieList: [Movie] = []
for try await page in pages {
guard let items = page.items else {
print("Error: no items returned.")
continue
}
// Convert the found movies into `Movie` objects and return an array
// of them.
for item in items {
let movie = try Movie(withItem: item)
movieList.append(movie)
}
}
return movieList
} catch {
print("ERROR: getMovies:", dump(error))
throw error
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Swift API 参考》**中的 [Query](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/query(input:))。
------
有关更多 DynamoDB 示例，请参阅[适用于使用 Amazon SDK 的 DynamoDB 的代码示例](service_code_examples.md)。
要为表创建全局二级索引，请继续 [第 6 步：（可选）删除 DynamoDB 表以清理资源](getting-started-step-6.md)。
# 第 6 步：（可选）删除 DynamoDB 表以清理资源
如果不再需要为本教程创建的 Amazon DynamoDB 表，可以删除。此步骤有助于确保不会为未使用的资源付费。可以使用 DynamoDB 控制台或 Amazon CLI 删除 [第 1 步：在 DynamoDB 中创建表](getting-started-step-1.md) 中创建的 `Music` 表。
有关 DynamoDB 中表操作的更多信息，请参阅 [使用 DynamoDB 中的表和数据](WorkingWithTables.md)。
## Amazon Web Services 管理控制台
使用控制台删除 `Music` 表：
1. 打开 DynamoDB 控制台：[https://console.aws.amazon.com/dynamodb/](https://console.amazonaws.cn/dynamodb/)。
1. 在左侧导航窗格中，选择 **表**。
1. 在表列表中，选中 **Music** 表旁边的复选框。
1. 选择**删除**。
## Amazon CLI
下面的 Amazon CLI 示例使用 `delete-table` 删除 `Music` 表。
```
aws dynamodb delete-table --table-name Music
```
## Amazon SDK
以下代码示例演示如何使用 Amazon SDK 删除 DynamoDB 表。
------
#### [ .NET ]
**适用于 .NET 的 Amazon SDK (v4)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/dotnetv4/DynamoDB#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
///
/// Deletes a DynamoDB table.
///
/// The name of the table to delete.
/// A Boolean value indicating the success of the operation.
public async Task DeleteTableAsync(string tableName)
{
try
{
var request = new DeleteTableRequest
{
TableName = tableName,
};
var response = await _amazonDynamoDB.DeleteTableAsync(request);
Console.WriteLine($"Table {response.TableDescription.TableName} successfully deleted.");
return true;
}
catch (ResourceNotFoundException ex)
{
Console.WriteLine($"Table {tableName} was not found and cannot be deleted. {ex.Message}");
return false;
}
catch (AmazonDynamoDBException ex)
{
Console.WriteLine($"An Amazon DynamoDB error occurred while deleting table {tableName}. {ex.Message}");
return false;
}
catch (Exception ex)
{
Console.WriteLine($"An error occurred while deleting table {tableName}. {ex.Message}");
return false;
}
}
```
+ 有关 API 详细信息，请参阅《适用于 .NET 的 Amazon SDK API Reference》**中的 [DeleteTable](https://docs.amazonaws.cn/goto/DotNetSDKV4/dynamodb-2012-08-10/DeleteTable)。
------
#### [ Bash ]
**Amazon CLI 及 Bash 脚本**
查看 GitHub，了解更多信息。查找完整示例，了解如何在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/aws-cli/bash-linux/dynamodb#code-examples)中进行设置和运行。
```
###############################################################################
# function dynamodb_delete_table
#
# This function deletes a DynamoDB table.
#
# Parameters:
# -n table_name -- The name of the table to delete.
#
# Returns:
# 0 - If successful.
# 1 - If it fails.
###############################################################################
function dynamodb_delete_table() {
local table_name response
local option OPTARG # Required to use getopts command in a function.
# bashsupport disable=BP5008
function usage() {
echo "function dynamodb_delete_table"
echo "Deletes an Amazon DynamoDB table."
echo " -n table_name -- The name of the table to delete."
echo ""
}
# Retrieve the calling parameters.
while getopts "n:h" option; do
case "${option}" in
n) table_name="${OPTARG}" ;;
h)
usage
return 0
;;
\?)
echo "Invalid parameter"
usage
return 1
;;
esac
done
export OPTIND=1
if [[ -z "$table_name" ]]; then
errecho "ERROR: You must provide a table name with the -n parameter."
usage
return 1
fi
iecho "Parameters:\n"
iecho " table_name: $table_name"
iecho ""
response=$(aws dynamodb delete-table \
--table-name "$table_name")
local error_code=${?}
if [[ $error_code -ne 0 ]]; then
aws_cli_error_log $error_code
errecho "ERROR: AWS reports delete-table operation failed.$response"
return 1
fi
return 0
}
```
本示例中使用的实用程序函数。
```
###############################################################################
# function iecho
#
# This function enables the script to display the specified text only if
# the global variable $VERBOSE is set to true.
###############################################################################
function iecho() {
if [[ $VERBOSE == true ]]; then
echo "$@"
fi
}
###############################################################################
# function errecho
#
# This function outputs everything sent to it to STDERR (standard error output).
###############################################################################
function errecho() {
printf "%s\n" "$*" 1>&2
}
##############################################################################
# function aws_cli_error_log()
#
# This function is used to log the error messages from the AWS CLI.
#
# See https://docs.aws.amazon.com/cli/latest/topic/return-codes.html#cli-aws-help-return-codes.
#
# The function expects the following argument:
# $1 - The error code returned by the AWS CLI.
#
# Returns:
# 0: - Success.
#
##############################################################################
function aws_cli_error_log() {
local err_code=$1
errecho "Error code : $err_code"
if [ "$err_code" == 1 ]; then
errecho " One or more S3 transfers failed."
elif [ "$err_code" == 2 ]; then
errecho " Command line failed to parse."
elif [ "$err_code" == 130 ]; then
errecho " Process received SIGINT."
elif [ "$err_code" == 252 ]; then
errecho " Command syntax invalid."
elif [ "$err_code" == 253 ]; then
errecho " The system environment or configuration was invalid."
elif [ "$err_code" == 254 ]; then
errecho " The service returned an error."
elif [ "$err_code" == 255 ]; then
errecho " 255 is a catch-all error."
fi
return 0
}
```
+ 有关 API 详细信息，请参阅《Amazon CLI 命令参考》**中的 [DeleteTable](https://docs.amazonaws.cn/goto/aws-cli/dynamodb-2012-08-10/DeleteTable)。
------
#### [ C\$1\$1 ]
**SDK for C\$1\$1**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/cpp/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
//! Delete an Amazon DynamoDB table.
/*!
\sa deleteTable()
\param tableName: The DynamoDB table name.
\param clientConfiguration: AWS client configuration.
\return bool: Function succeeded.
*/
bool AwsDoc::DynamoDB::deleteTable(const Aws::String &tableName,
const Aws::Client::ClientConfiguration &clientConfiguration) {
Aws::DynamoDB::DynamoDBClient dynamoClient(clientConfiguration);
Aws::DynamoDB::Model::DeleteTableRequest request;
request.SetTableName(tableName);
const Aws::DynamoDB::Model::DeleteTableOutcome &result = dynamoClient.DeleteTable(
request);
if (result.IsSuccess()) {
std::cout << "Your table \""
<< result.GetResult().GetTableDescription().GetTableName()
<< " was deleted.\n";
}
else {
std::cerr << "Failed to delete table: " << result.GetError().GetMessage()
<< std::endl;
}
return result.IsSuccess();
}
```
+ 有关 API 详细信息，请参阅《适用于 C\$1\$1 的 Amazon SDK API Reference》**中的 [DeleteTable](https://docs.amazonaws.cn/goto/SdkForCpp/dynamodb-2012-08-10/DeleteTable)。
------
#### [ CLI ]
**Amazon CLI**
**删除表**
以下 `delete-table` 示例将删除 `MusicCollection` 表。
```
aws dynamodb delete-table \
--table-name MusicCollection
```
输出：
```
{
"TableDescription": {
"TableStatus": "DELETING",
"TableSizeBytes": 0,
"ItemCount": 0,
"TableName": "MusicCollection",
"ProvisionedThroughput": {
"NumberOfDecreasesToday": 0,
"WriteCapacityUnits": 5,
"ReadCapacityUnits": 5
}
}
}
```
有关更多信息，请参阅《Amazon DynamoDB 开发人员指南》**中的[删除表](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/WorkingWithTables.Basics.html#WorkingWithTables.Basics.DeleteTable)。
+ 有关 API 详细信息，请参阅《Amazon CLI 命令参考》**中的 [DeleteTable](https://awscli.amazonaws.com/v2/documentation/api/latest/reference/dynamodb/delete-table.html)。
------
#### [ Go ]
**适用于 Go 的 SDK V2**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/gov2/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
import (
"context"
"errors"
"log"
"time"
"github.com/aws/aws-sdk-go-v2/aws"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/attributevalue"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
"github.com/aws/aws-sdk-go-v2/service/dynamodb"
"github.com/aws/aws-sdk-go-v2/service/dynamodb/types"
)
// TableBasics encapsulates the Amazon DynamoDB service actions used in the examples.
// It contains a DynamoDB service client that is used to act on the specified table.
type TableBasics struct {
DynamoDbClient *dynamodb.Client
TableName string
}
// DeleteTable deletes the DynamoDB table and all of its data.
func (basics TableBasics) DeleteTable(ctx context.Context) error {
_, err := basics.DynamoDbClient.DeleteTable(ctx, &dynamodb.DeleteTableInput{
TableName: aws.String(basics.TableName)})
if err != nil {
log.Printf("Couldn't delete table %v. Here's why: %v\n", basics.TableName, err)
}
return err
}
```
+ 有关 API 详细信息，请参阅《适用于 Go 的 Amazon SDK API Reference》**中的 [DeleteTable](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/dynamodb#Client.DeleteTable)。
------
#### [ Java ]
**适用于 Java 的 SDK 2.x**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javav2/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.dynamodb.model.DynamoDbException;
import software.amazon.awssdk.services.dynamodb.DynamoDbClient;
import software.amazon.awssdk.services.dynamodb.model.DeleteTableRequest;
/**
* Before running this Java V2 code example, set up your development
* environment, including your credentials.
*
* For more information, see the following documentation topic:
*
* https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/get-started.html
*/
public class DeleteTable {
public static void main(String[] args) {
final String usage = """
Usage:
Where:
tableName - The Amazon DynamoDB table to delete (for example, Music3).
**Warning** This program will delete the table that you specify!
""";
if (args.length != 1) {
System.out.println(usage);
System.exit(1);
}
String tableName = args[0];
System.out.format("Deleting the Amazon DynamoDB table %s...\n", tableName);
Region region = Region.US_EAST_1;
DynamoDbClient ddb = DynamoDbClient.builder()
.region(region)
.build();
deleteDynamoDBTable(ddb, tableName);
ddb.close();
}
public static void deleteDynamoDBTable(DynamoDbClient ddb, String tableName) {
DeleteTableRequest request = DeleteTableRequest.builder()
.tableName(tableName)
.build();
try {
ddb.deleteTable(request);
} catch (DynamoDbException e) {
System.err.println(e.getMessage());
System.exit(1);
}
System.out.println(tableName + " was successfully deleted!");
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Java 2.x API Reference》**中的 [DeleteTable](https://docs.amazonaws.cn/goto/SdkForJavaV2/dynamodb-2012-08-10/DeleteTable)。
------
#### [ JavaScript ]
**SDK for JavaScript (v3)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascriptv3/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
import { DeleteTableCommand, DynamoDBClient } from "@aws-sdk/client-dynamodb";
const client = new DynamoDBClient({});
export const main = async () => {
const command = new DeleteTableCommand({
TableName: "DecafCoffees",
});
const response = await client.send(command);
console.log(response);
return response;
};
```
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 Amazon SDK API Reference》**中的 [DeleteTable](https://docs.amazonaws.cn/AWSJavaScriptSDK/v3/latest/client/dynamodb/command/DeleteTableCommand)。
**SDK for JavaScript (v2)**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/javascript/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
// Load the AWS SDK for Node.js
var AWS = require("aws-sdk");
// Set the region
AWS.config.update({ region: "REGION" });
// Create the DynamoDB service object
var ddb = new AWS.DynamoDB({ apiVersion: "2012-08-10" });
var params = {
TableName: process.argv[2],
};
// Call DynamoDB to delete the specified table
ddb.deleteTable(params, function (err, data) {
if (err && err.code === "ResourceNotFoundException") {
console.log("Error: Table not found");
} else if (err && err.code === "ResourceInUseException") {
console.log("Error: Table in use");
} else {
console.log("Success", data);
}
});
```
+ 有关更多信息，请参阅《适用于 JavaScript 的 Amazon SDK 开发人员指南》[https://docs.amazonaws.cn/sdk-for-javascript/v2/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-deleting-a-table](https://docs.amazonaws.cn/sdk-for-javascript/v2/developer-guide/dynamodb-examples-using-tables.html#dynamodb-examples-using-tables-deleting-a-table)。
+ 有关 API 详细信息，请参阅《适用于 JavaScript 的 Amazon SDK API Reference》**中的 [DeleteTable](https://docs.amazonaws.cn/goto/AWSJavaScriptSDK/dynamodb-2012-08-10/DeleteTable)。
------
#### [ Kotlin ]
**SDK for Kotlin**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/kotlin/services/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
suspend fun deleteDynamoDBTable(tableNameVal: String) {
val request =
DeleteTableRequest {
tableName = tableNameVal
}
DynamoDbClient.fromEnvironment { region = "us-east-1" }.use { ddb ->
ddb.deleteTable(request)
println("$tableNameVal was deleted")
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Kotlin API Reference》**中的 [DeleteTable](https://sdk.amazonaws.com/kotlin/api/latest/index.html)。
------
#### [ PHP ]
**适用于 PHP 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
public function deleteTable(string $TableName)
{
$this->customWaiter(function () use ($TableName) {
return $this->dynamoDbClient->deleteTable([
'TableName' => $TableName,
]);
});
}
```
+ 有关 API 详细信息，请参阅《适用于 PHP 的 Amazon SDK API Reference》**中的 [DeleteTable](https://docs.amazonaws.cn/goto/SdkForPHPV3/dynamodb-2012-08-10/DeleteTable)。
------
#### [ PowerShell ]
**适用于 PowerShell V4 的工具**
**示例 1：删除指定的表。在操作继续之前，系统会提示您进行确认。**
```
Remove-DDBTable -TableName "myTable"
```
**示例 2：删除指定的表。在操作继续之前，系统不会提示您进行确认。**
```
Remove-DDBTable -TableName "myTable" -Force
```
+ 有关 API 详细信息，请参阅《Amazon Tools for PowerShell Cmdlet Reference (V4)》**中的 [DeleteTable](https://docs.amazonaws.cn/powershell/v4/reference)。
**适用于 PowerShell V5 的工具**
**示例 1：删除指定的表。在操作继续之前，系统会提示您进行确认。**
```
Remove-DDBTable -TableName "myTable"
```
**示例 2：删除指定的表。在操作继续之前，系统不会提示您进行确认。**
```
Remove-DDBTable -TableName "myTable" -Force
```
+ 有关 API 详细信息，请参阅《Amazon Tools for PowerShell Cmdlet Reference (V5)》**中的 [DeleteTable](https://docs.amazonaws.cn/powershell/v5/reference)。
------
#### [ Python ]
**适用于 Python 的 SDK（Boto3）**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/python/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
class Movies:
"""Encapsulates an Amazon DynamoDB table of movie data.
Example data structure for a movie record in this table:
{
"year": 1999,
"title": "For Love of the Game",
"info": {
"directors": ["Sam Raimi"],
"release_date": "1999-09-15T00:00:00Z",
"rating": 6.3,
"plot": "A washed up pitcher flashes through his career.",
"rank": 4987,
"running_time_secs": 8220,
"actors": [
"Kevin Costner",
"Kelly Preston",
"John C. Reilly"
]
}
}
"""
def __init__(self, dyn_resource):
"""
:param dyn_resource: A Boto3 DynamoDB resource.
"""
self.dyn_resource = dyn_resource
# The table variable is set during the scenario in the call to
# 'exists' if the table exists. Otherwise, it is set by 'create_table'.
self.table = None
def delete_table(self):
"""
Deletes the table.
"""
try:
self.table.delete()
self.table = None
except ClientError as err:
logger.error(
"Couldn't delete table. Here's why: %s: %s",
err.response["Error"]["Code"],
err.response["Error"]["Message"],
)
raise
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Python (Boto3) API Reference》**中的 [DeleteTable](https://docs.amazonaws.cn/goto/boto3/dynamodb-2012-08-10/DeleteTable)。
------
#### [ Ruby ]
**适用于 Ruby 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/ruby/example_code/dynamodb#code-examples) 中查找完整示例，了解如何进行设置和运行。
```
# Encapsulates an Amazon DynamoDB table of movie data.
class Scaffold
attr_reader :dynamo_resource, :table_name, :table
def initialize(table_name)
client = Aws::DynamoDB::Client.new(region: 'us-east-1')
@dynamo_resource = Aws::DynamoDB::Resource.new(client: client)
@table_name = table_name
@table = nil
@logger = Logger.new($stdout)
@logger.level = Logger::DEBUG
end
# Deletes the table.
def delete_table
@table.delete
@table = nil
rescue Aws::DynamoDB::Errors::ServiceError => e
puts("Couldn't delete table. Here's why:")
puts("\t#{e.code}: #{e.message}")
raise
end
```
+ 有关 API 详细信息，请参阅《适用于 Ruby 的 Amazon SDK API Reference》**中的 [DeleteTable](https://docs.amazonaws.cn/goto/SdkForRubyV3/dynamodb-2012-08-10/DeleteTable)。
------
#### [ Rust ]
**适用于 Rust 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/rustv1/examples/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
pub async fn delete_table(client: &Client, table: &str) -> Result {
let resp = client.delete_table().table_name(table).send().await;
match resp {
Ok(out) => {
println!("Deleted table");
Ok(out)
}
Err(e) => Err(Error::Unhandled(e.into())),
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Rust API Reference》**中的 [DeleteTable](https://docs.rs/aws-sdk-dynamodb/latest/aws_sdk_dynamodb/client/struct.Client.html#method.delete_table)。
------
#### [ SAP ABAP ]
**适用于 SAP ABAP 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/sap-abap/services/dyn#code-examples)中查找完整示例，了解如何进行设置和运行。
```
TRY.
lo_dyn->deletetable( iv_tablename = iv_table_name ).
" Wait till the table is actually deleted.
lo_dyn->get_waiter( )->tablenotexists(
iv_max_wait_time = 200
iv_tablename = iv_table_name ).
MESSAGE 'Table ' && iv_table_name && ' deleted.' TYPE 'I'.
CATCH /aws1/cx_dynresourcenotfoundex.
MESSAGE 'The table ' && iv_table_name && ' does not exist' TYPE 'E'.
CATCH /aws1/cx_dynresourceinuseex.
MESSAGE 'The table cannot be deleted since it is in use' TYPE 'E'.
ENDTRY.
```
+ 有关 API 详细信息，请参阅《Amazon SDK for SAP ABAP API Reference》**中的 [DeleteTable](https://docs.amazonaws.cn/sdk-for-sap-abap/v1/api/latest/index.html)。
------
#### [ Swift ]
**适用于 Swift 的 SDK**
查看 GitHub，了解更多信息。在 [Amazon 代码示例存储库](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/swift/example_code/dynamodb#code-examples)中查找完整示例，了解如何进行设置和运行。
```
import AWSDynamoDB
///
/// Deletes the table from Amazon DynamoDB.
///
func deleteTable() async throws {
do {
guard let client = self.ddbClient else {
throw MoviesError.UninitializedClient
}
let input = DeleteTableInput(
tableName: self.tableName
)
_ = try await client.deleteTable(input: input)
} catch {
print("ERROR: deleteTable:", dump(error))
throw error
}
}
```
+ 有关 API 详细信息，请参阅《Amazon SDK for Swift API Reference》**中的 [DeleteTable](https://sdk.amazonaws.com/swift/api/awsdynamodb/latest/documentation/awsdynamodb/dynamodbclient/deletetable(input:))。
------
有关更多 DynamoDB 示例，请参阅[适用于使用 Amazon SDK 的 DynamoDB 的代码示例](service_code_examples.md)。
# 继续了解 DynamoDB
有关 Amazon DynamoDB 的更多信息，请参见以下主题：
+ [使用 DynamoDB 中的表和数据](WorkingWithTables.md)
+ [使用 DynamoDB 中的项目和属性](WorkingWithItems.md)
+ [在 DynamoDB 中查询表](Query.md)
+ [在 DynamoDB 中使用全局二级索引](GSI.md)
+ [使用事务代码示例](transactions.md)
+ [利用 DynamoDB Accelerator（DAX）实现内存中加速](DAX.md)
+ [使用 DynamoDB 和 Amazon SDK 编程](Programming.md)
# 使用 Console-to-Code 为 Amazon DynamoDB 生成基础设施代码
Amazon Q 开发者版的 Console-to-Code 功能可将手动创建表的步骤转换为可重用的自动化代码，从而简化 Amazon DynamoDB 的基础设施管理。此功能可帮助开发人员在其环境中高效地扩展数据库资源配置。要了解更多信息，请参阅[使用 Amazon Q 开发者版 Console-to-Code 实现 Amazon Web Services 服务自动化](https://docs.amazonaws.cn/amazonq/latest/qdeveloper-ug/console-to-code.html)。
Console-to-Code 采集详细的 DynamoDB 表配置，包括分区键、排序键、预调配吞吐量设置和二级索引，并将它们转换为精确的基础设施即代码模板。该工具使用生成式人工智能，可确保生成的代码保持在控制台工作流中建立的参数兼容性。
开发人员可以生成多种格式的 DynamoDB 基础设施代码，例如：
+ Amazon 云开发工具包（Amazon CDK），使用 TypeScript、Python 和 Java 格式
+ Amazon CloudFormation，使用 YAML 或 JSON 格式
这种方法使团队能够：
+ 标准化数据库资源管理
+ 实施版本控制的基础设施
+ 减少手动配置错误
适用于 Amazon DynamoDB 的 Console-to-Code 在所有商业 Amazon 区域中可用，为将手动配置过程转换为自动化、可复制的基础设施代码提供了强大的解决方案。
## 工作原理
在 DynamoDB 中使用 Console-to-Code 时，该过程通常涉及：
1. **在控制台中创建原型**：使用 DynamoDB 控制台创建和配置资源，例如表。有关更多信息，请参阅[连接到 Amazon DynamoDB](https://docs.amazonaws.cn/amazondynamodb/latest/developerguide/GettingStartedDynamoDB.html)。
1. **记录操作**：Console-to-Code 会在您执行操作时记录这些操作。
1. **代码生成**：该功能使用 Amazon Q 开发者版的生成式人工智能功能，使用您的首选格式，将控制台中的操作转换为可重复使用的代码。
1. **代码自定义**：然后，您可以复制或下载此代码，并针对您的生产工作负载对其进行进一步自定义。
## 在 DynamoDB 中使用 Console-to-Code 的好处
**简化自动化过程**
只需一次单击，即可将 DynamoDB 表的手动创建和配置过程转换为可重复使用的代码。
**最佳实践**
生成的代码遵循 Amazon 指导性最佳实践，实现可靠部署。
**控制台和代码之间的桥梁**
您不必在使用 Amazon Web Services 管理控制台或基础设施即代码（IaC）之间做出选择。而是可以同时使用这两种方法。
**加速开发过程**
使用自动化代码快速上手，这些代码可以进一步定制来供生产使用。
## 使用案例示例
+ 使用特定属性、键和容量设置创建 DynamoDB 表
+ 设置全局二级索引和本地二级索引
+ 为 DynamoDB 表配置自动扩缩策略
+ 建立备份和还原配置
+ 创建和管理 DynamoDB Streams
## 开始使用
要开始在 DynamoDB 中使用 Console-to-Code，请执行以下操作：
1. 登录 Amazon Web Services 管理控制台，打开 DynamoDB 控制台：[https://console.aws.amazon.com/dynamodbv2/](https://console.amazonaws.cn/dynamodbv2/)。
1. 通过控制台界面开始创建或修改 DynamoDB 资源。
1. 使用 Console-to-Code 功能，按照您的首选格式为操作生成代码。
1. 复制或下载生成的代码，并根据您的具体需求对其进行自定义。
有关如何使用 Console-to-Code 的更多信息和详细说明，请参阅《Amazon Q 开发者版用户指南》**中的[使用 Amazon Q 开发者版 Console-to-Code 实现 Amazon Web Services 服务自动化](https://docs.amazonaws.cn/amazonq/latest/qdeveloper-ug/console-to-code.html)。