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Class: Aws::DynamoDB::Table

Inherits:
Resources::Resource show all
Defined in:
(unknown)

Instance Attribute Summary collapse

Attributes inherited from Resources::Resource

#client, #identifiers

Instance Method Summary collapse

Methods inherited from Resources::Resource

add_data_attribute, add_identifier, #data, data_attributes, #data_loaded?, identifiers, #load, #wait_until

Methods included from Resources::OperationMethods

#add_batch_operation, #add_operation, #batch_operation, #batch_operation_names, #batch_operations, #operation, #operation_names, #operations

Constructor Details

#initialize(name, options = {}) ⇒ Object #initialize(options = {}) ⇒ Object

Overloads:

  • #initialize(name, options = {}) ⇒ Object

    Parameters:

    • name (String)

    Options Hash (options):

    • :client (Client) —

      When `:client is not given, the options hash is used to construct a new Client object.

  • #initialize(options = {}) ⇒ Object

    Options Hash (options):

    • :name (required, String)
    • :client (Client) —

      When `:client is not given, the options hash is used to construct a new Client object.

Instance Attribute Details

#archival_summary ⇒ Types::ArchivalSummary (readonly)

Contains information about the table archive.

Returns:

#attribute_definitions ⇒ Array<Types::AttributeDefinition> (readonly)

An array of AttributeDefinition objects. Each of these objects describes one attribute in the table and index key schema.

Each AttributeDefinition object in this array is composed of:

  • AttributeName - The name of the attribute.

  • AttributeType - The data type for the attribute.

Returns:

#billing_mode_summary ⇒ Types::BillingModeSummary (readonly)

Contains the details for the read/write capacity mode.

Returns:

#creation_date_time ⇒ Time (readonly)

The date and time when the table was created, in UNIX epoch time format.

Returns:

  • (Time) —

    The date and time when the table was created, in [UNIX epoch time][1] format.

#global_secondary_indexes ⇒ Array<Types::GlobalSecondaryIndexDescription> (readonly)

The global secondary indexes, if any, on the table. Each index is scoped to a given partition key value. Each element is composed of:

  • Backfilling - If true, then the index is currently in the backfilling phase. Backfilling occurs only when a new global secondary index is added to the table. It is the process by which DynamoDB populates the new index with data from the table. (This attribute does not appear for indexes that were created during a CreateTable operation.)

    You can delete an index that is being created during the Backfilling phase when IndexStatus is set to CREATING and Backfilling is true. You can\'t delete the index that is being created when IndexStatus is set to CREATING and Backfilling is false. (This attribute does not appear for indexes that were created during a CreateTable operation.)

  • IndexName - The name of the global secondary index.

  • IndexSizeBytes - The total size of the global secondary index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.

  • IndexStatus - The current status of the global secondary index:

    • CREATING - The index is being created.

    • UPDATING - The index is being updated.

    • DELETING - The index is being deleted.

    • ACTIVE - The index is ready for use.

  • ItemCount - The number of items in the global secondary index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.

  • KeySchema - Specifies the complete index key schema. The attribute names in the key schema must be between 1 and 255 characters (inclusive). The key schema must begin with the same partition key as the table.

  • Projection - Specifies attributes that are copied (projected) from the table into the index. These are in addition to the primary key attributes and index key attributes, which are automatically projected. Each attribute specification is composed of:

    • ProjectionType - One of the following:

      • KEYS_ONLY - Only the index and primary keys are projected into the index.

      • INCLUDE - In addition to the attributes described in KEYS_ONLY, the secondary index will include other non-key attributes that you specify.

      • ALL - All of the table attributes are projected into the index.

    • NonKeyAttributes - A list of one or more non-key attribute names that are projected into the secondary index. The total count of attributes provided in NonKeyAttributes, summed across all of the secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.

  • ProvisionedThroughput - The provisioned throughput settings for the global secondary index, consisting of read and write capacity units, along with data about increases and decreases.

If the table is in the DELETING state, no information about indexes will be returned.

Returns:

#global_table_version ⇒ String (readonly)

Represents the version of global tables in use, if the table is replicated across AWS Regions.

Returns:

  • (String) —

    Represents the version of [global tables][1] in use, if the table is replicated across AWS Regions.

#item_count ⇒ Integer (readonly)

The number of items in the specified table. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.

Returns:

  • (Integer) —

    The number of items in the specified table.

#key_schema ⇒ Array<Types::KeySchemaElement> (readonly)

The primary key structure for the table. Each KeySchemaElement consists of:

  • AttributeName - The name of the attribute.

  • KeyType - The role of the attribute:

    • HASH - partition key

    • RANGE - sort key

    The partition key of an item is also known as its hash attribute. The term \"hash attribute\" derives from DynamoDB\'s usage of an internal hash function to evenly distribute data items across partitions, based on their partition key values.

    The sort key of an item is also known as its range attribute. The term \"range attribute\" derives from the way DynamoDB stores items with the same partition key physically close together, in sorted order by the sort key value.

For more information about primary keys, see Primary Key in the Amazon DynamoDB Developer Guide.

Returns:

#latest_stream_arn ⇒ String (readonly)

The Amazon Resource Name (ARN) that uniquely identifies the latest stream for this table.

Returns:

  • (String) —

    The Amazon Resource Name (ARN) that uniquely identifies the latest stream for this table.

#latest_stream_label ⇒ String (readonly)

A timestamp, in ISO 8601 format, for this stream.

Note that LatestStreamLabel is not a unique identifier for the stream, because it is possible that a stream from another table might have the same timestamp. However, the combination of the following three elements is guaranteed to be unique:

  • AWS customer ID

  • Table name

  • StreamLabel

Returns:

  • (String) —

    A timestamp, in ISO 8601 format, for this stream.

#local_secondary_indexes ⇒ Array<Types::LocalSecondaryIndexDescription> (readonly)

Represents one or more local secondary indexes on the table. Each index is scoped to a given partition key value. Tables with one or more local secondary indexes are subject to an item collection size limit, where the amount of data within a given item collection cannot exceed 10 GB. Each element is composed of:

  • IndexName - The name of the local secondary index.

  • KeySchema - Specifies the complete index key schema. The attribute names in the key schema must be between 1 and 255 characters (inclusive). The key schema must begin with the same partition key as the table.

  • Projection - Specifies attributes that are copied (projected) from the table into the index. These are in addition to the primary key attributes and index key attributes, which are automatically projected. Each attribute specification is composed of:

    • ProjectionType - One of the following:

      • KEYS_ONLY - Only the index and primary keys are projected into the index.

      • INCLUDE - Only the specified table attributes are projected into the index. The list of projected attributes is in NonKeyAttributes.

      • ALL - All of the table attributes are projected into the index.

    • NonKeyAttributes - A list of one or more non-key attribute names that are projected into the secondary index. The total count of attributes provided in NonKeyAttributes, summed across all of the secondary indexes, must not exceed 20. If you project the same attribute into two different indexes, this counts as two distinct attributes when determining the total.

  • IndexSizeBytes - Represents the total size of the index, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.

  • ItemCount - Represents the number of items in the index. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.

If the table is in the DELETING state, no information about indexes will be returned.

Returns:

#name ⇒ String (readonly)

Returns:

  • (String)

#provisioned_throughput ⇒ Types::ProvisionedThroughputDescription (readonly)

The provisioned throughput settings for the table, consisting of read and write capacity units, along with data about increases and decreases.

Returns:

#replicas ⇒ Array<Types::ReplicaDescription> (readonly)

Represents replicas of the table.

Returns:

#restore_summary ⇒ Types::RestoreSummary (readonly)

Contains details for the restore.

Returns:

#sse_description ⇒ Types::SSEDescription (readonly)

The description of the server-side encryption status on the specified table.

Returns:

  • (Types::SSEDescription) —

    The description of the server-side encryption status on the specified table.

#stream_specification ⇒ Types::StreamSpecification (readonly)

The current DynamoDB Streams configuration for the table.

Returns:

#table_arn ⇒ String (readonly)

The Amazon Resource Name (ARN) that uniquely identifies the table.

Returns:

  • (String) —

    The Amazon Resource Name (ARN) that uniquely identifies the table.

#table_id ⇒ String (readonly)

Unique identifier for the table for which the backup was created.

Returns:

  • (String) —

    Unique identifier for the table for which the backup was created.

#table_name ⇒ String (readonly)

The name of the table.

Returns:

  • (String) —

    The name of the table.

#table_size_bytes ⇒ Integer (readonly)

The total size of the specified table, in bytes. DynamoDB updates this value approximately every six hours. Recent changes might not be reflected in this value.

Returns:

  • (Integer) —

    The total size of the specified table, in bytes.

#table_status ⇒ String (readonly)

The current state of the table:

  • CREATING - The table is being created.

  • UPDATING - The table is being updated.

  • DELETING - The table is being deleted.

  • ACTIVE - The table is ready for use.

  • INACCESSIBLE_ENCRYPTION_CREDENTIALS - The AWS KMS key used to encrypt the table in inaccessible. Table operations may fail due to failure to use the AWS KMS key. DynamoDB will initiate the table archival process when a table\'s AWS KMS key remains inaccessible for more than seven days.

  • ARCHIVING - The table is being archived. Operations are not allowed until archival is complete.

  • ARCHIVED - The table has been archived. See the ArchivalReason for more information.

    Possible values:

    • CREATING
    • UPDATING
    • DELETING
    • ACTIVE
    • INACCESSIBLE_ENCRYPTION_CREDENTIALS
    • ARCHIVING
    • ARCHIVED

Returns:

  • (String) —

    The current state of the table:.

Instance Method Details

#delete ⇒ Types::DeleteTableOutput

The DeleteTable operation deletes a table and all of its items. After a DeleteTable request, the specified table is in the DELETING state until DynamoDB completes the deletion. If the table is in the ACTIVE state, you can delete it. If a table is in CREATING or UPDATING states, then DynamoDB returns a ResourceInUseException. If the specified table does not exist, DynamoDB returns a ResourceNotFoundException. If table is already in the DELETING state, no error is returned.

DynamoDB might continue to accept data read and write operations, such as GetItem and PutItem, on a table in the DELETING state until the table deletion is complete.

When you delete a table, any indexes on that table are also deleted.

If you have DynamoDB Streams enabled on the table, then the corresponding stream on that table goes into the DISABLED state, and the stream is automatically deleted after 24 hours.

Use the DescribeTable action to check the status of the table.

Examples:

Request syntax example with placeholder values


table.delete()

Returns:

See Also:

#delete_item(options = {}) ⇒ Types::DeleteItemOutput

Deletes a single item in a table by primary key. You can perform a conditional delete operation that deletes the item if it exists, or if it has an expected attribute value.

In addition to deleting an item, you can also return the item's attribute values in the same operation, using the ReturnValues parameter.

Unless you specify conditions, the DeleteItem is an idempotent operation; running it multiple times on the same item or attribute does not result in an error response.

Conditional deletes are useful for deleting items only if specific conditions are met. If those conditions are met, DynamoDB performs the delete. Otherwise, the item is not deleted.

Examples:

Request syntax example with placeholder values


table.delete_item({
  key: { # required
    "AttributeName" => "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
  },
  expected: {
    "AttributeName" => {
      value: "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
      exists: false,
      comparison_operator: "EQ", # accepts EQ, NE, IN, LE, LT, GE, GT, BETWEEN, NOT_NULL, NULL, CONTAINS, NOT_CONTAINS, BEGINS_WITH
      attribute_value_list: ["value"], # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
    },
  },
  conditional_operator: "AND", # accepts AND, OR
  return_values: "NONE", # accepts NONE, ALL_OLD, UPDATED_OLD, ALL_NEW, UPDATED_NEW
  return_consumed_capacity: "INDEXES", # accepts INDEXES, TOTAL, NONE
  return_item_collection_metrics: "SIZE", # accepts SIZE, NONE
  condition_expression: "ConditionExpression",
  expression_attribute_names: {
    "ExpressionAttributeNameVariable" => "AttributeName",
  },
  expression_attribute_values: {
    "ExpressionAttributeValueVariable" => "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
  },
})

Options Hash (options):

  • :key (required, Hash<String,Types::AttributeValue>) —

    A map of attribute names to AttributeValue objects, representing the primary key of the item to delete.

    For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.

  • :expected (Hash<String,Types::ExpectedAttributeValue>) —

    This is a legacy parameter. Use ConditionExpression instead. For more information, see Expected in the Amazon DynamoDB Developer Guide.

  • :conditional_operator (String) —

    This is a legacy parameter. Use ConditionExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.

  • :return_values (String) —

    Use ReturnValues if you want to get the item attributes as they appeared before they were deleted. For DeleteItem, the valid values are:

    • NONE - If ReturnValues is not specified, or if its value is NONE, then nothing is returned. (This setting is the default for ReturnValues.)

    • ALL_OLD - The content of the old item is returned.

    The ReturnValues parameter is used by several DynamoDB operations; however, DeleteItem does not recognize any values other than NONE or ALL_OLD.

  • :return_consumed_capacity (String) —

    Determines the level of detail about provisioned throughput consumption that is returned in the response:

    • INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed.

      Note that some operations, such as GetItem and BatchGetItem, do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).

    • TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.

    • NONE - No ConsumedCapacity details are included in the response.

  • :return_item_collection_metrics (String) —

    Determines whether item collection metrics are returned. If set to SIZE, the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to NONE (the default), no statistics are returned.

  • :condition_expression (String) —

    A condition that must be satisfied in order for a conditional DeleteItem to succeed.

    An expression can contain any of the following:

    • Functions: attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size

      These function names are case-sensitive.

    • Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN

    • Logical operators: AND | OR | NOT

    For more information about condition expressions, see Condition Expressions in the Amazon DynamoDB Developer Guide.

  • :expression_attribute_names (Hash<String,String>) —

    One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

    • To access an attribute whose name conflicts with a DynamoDB reserved word.

    • To create a placeholder for repeating occurrences of an attribute name in an expression.

    • To prevent special characters in an attribute name from being misinterpreted in an expression.

    Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

    • Percentile

    ^

    The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

    • `{"#P":"Percentile"}`

    ^

    You could then use this substitution in an expression, as in this example:

    • #P = :val

    ^

    Tokens that begin with the : character are expression attribute values, which are placeholders for the actual value at runtime.

    For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

  • :expression_attribute_values (Hash<String,Types::AttributeValue>) —

    One or more values that can be substituted in an expression.

    Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:

    Available | Backordered | Discontinued

    You would first need to specify ExpressionAttributeValues as follows:

    { ":avail":`{"S":"Available"}`, ":back":`{"S":"Backordered"}`, ":disc":`{"S":"Discontinued"}` }

    You could then use these values in an expression, such as this:

    ProductStatus IN (:avail, :back, :disc)

    For more information on expression attribute values, see Condition Expressions in the Amazon DynamoDB Developer Guide.

Returns:

See Also:

#get_item(options = {}) ⇒ Types::GetItemOutput

The GetItem operation returns a set of attributes for the item with the given primary key. If there is no matching item, GetItem does not return any data and there will be no Item element in the response.

GetItem provides an eventually consistent read by default. If your application requires a strongly consistent read, set ConsistentRead to true. Although a strongly consistent read might take more time than an eventually consistent read, it always returns the last updated value.

Examples:

Request syntax example with placeholder values


table.get_item({
  key: { # required
    "AttributeName" => "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
  },
  attributes_to_get: ["AttributeName"],
  consistent_read: false,
  return_consumed_capacity: "INDEXES", # accepts INDEXES, TOTAL, NONE
  projection_expression: "ProjectionExpression",
  expression_attribute_names: {
    "ExpressionAttributeNameVariable" => "AttributeName",
  },
})

Options Hash (options):

  • :key (required, Hash<String,Types::AttributeValue>) —

    A map of attribute names to AttributeValue objects, representing the primary key of the item to retrieve.

    For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.

  • :attributes_to_get (Array<String>) —

    This is a legacy parameter. Use ProjectionExpression instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.

  • :consistent_read (Boolean) —

    Determines the read consistency model: If set to true, then the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.

  • :return_consumed_capacity (String) —

    Determines the level of detail about provisioned throughput consumption that is returned in the response:

    • INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed.

      Note that some operations, such as GetItem and BatchGetItem, do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).

    • TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.

    • NONE - No ConsumedCapacity details are included in the response.

  • :projection_expression (String) —

    A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.

    If no attribute names are specified, then all attributes are returned. If any of the requested attributes are not found, they do not appear in the result.

    For more information, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

  • :expression_attribute_names (Hash<String,String>) —

    One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

    • To access an attribute whose name conflicts with a DynamoDB reserved word.

    • To create a placeholder for repeating occurrences of an attribute name in an expression.

    • To prevent special characters in an attribute name from being misinterpreted in an expression.

    Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

    • Percentile

    ^

    The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

    • `{"#P":"Percentile"}`

    ^

    You could then use this substitution in an expression, as in this example:

    • #P = :val

    ^

    Tokens that begin with the : character are expression attribute values, which are placeholders for the actual value at runtime.

    For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

Returns:

See Also:

#put_item(options = {}) ⇒ Types::PutItemOutput

Creates a new item, or replaces an old item with a new item. If an item that has the same primary key as the new item already exists in the specified table, the new item completely replaces the existing item. You can perform a conditional put operation (add a new item if one with the specified primary key doesn't exist), or replace an existing item if it has certain attribute values. You can return the item's attribute values in the same operation, using the ReturnValues parameter.

This topic provides general information about the PutItem API.

For information on how to call the PutItem API using the AWS SDK in specific languages, see the following:

When you add an item, the primary key attributes are the only required attributes. Attribute values cannot be null.

Empty String and Binary attribute values are allowed. Attribute values of type String and Binary must have a length greater than zero if the attribute is used as a key attribute for a table or index. Set type attributes cannot be empty.

Invalid Requests with empty values will be rejected with a ValidationException exception.

To prevent a new item from replacing an existing item, use a conditional expression that contains the attribute_not_exists function with the name of the attribute being used as the partition key for the table. Since every record must contain that attribute, the attribute_not_exists function will only succeed if no matching item exists.

For more information about PutItem, see Working with Items in the Amazon DynamoDB Developer Guide.

Examples:

Request syntax example with placeholder values


table.put_item({
  item: { # required
    "AttributeName" => "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
  },
  expected: {
    "AttributeName" => {
      value: "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
      exists: false,
      comparison_operator: "EQ", # accepts EQ, NE, IN, LE, LT, GE, GT, BETWEEN, NOT_NULL, NULL, CONTAINS, NOT_CONTAINS, BEGINS_WITH
      attribute_value_list: ["value"], # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
    },
  },
  return_values: "NONE", # accepts NONE, ALL_OLD, UPDATED_OLD, ALL_NEW, UPDATED_NEW
  return_consumed_capacity: "INDEXES", # accepts INDEXES, TOTAL, NONE
  return_item_collection_metrics: "SIZE", # accepts SIZE, NONE
  conditional_operator: "AND", # accepts AND, OR
  condition_expression: "ConditionExpression",
  expression_attribute_names: {
    "ExpressionAttributeNameVariable" => "AttributeName",
  },
  expression_attribute_values: {
    "ExpressionAttributeValueVariable" => "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
  },
})

Options Hash (options):

  • :item (required, Hash<String,Types::AttributeValue>) —

    A map of attribute name/value pairs, one for each attribute. Only the primary key attributes are required; you can optionally provide other attribute name-value pairs for the item.

    You must provide all of the attributes for the primary key. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide both values for both the partition key and the sort key.

    If you specify any attributes that are part of an index key, then the data types for those attributes must match those of the schema in the table\'s attribute definition.

    Empty String and Binary attribute values are allowed. Attribute values of type String and Binary must have a length greater than zero if the attribute is used as a key attribute for a table or index.

    For more information about primary keys, see Primary Key in the Amazon DynamoDB Developer Guide.

    Each element in the Item map is an AttributeValue object.

  • :expected (Hash<String,Types::ExpectedAttributeValue>) —

    This is a legacy parameter. Use ConditionExpression instead. For more information, see Expected in the Amazon DynamoDB Developer Guide.

  • :return_values (String) —

    Use ReturnValues if you want to get the item attributes as they appeared before they were updated with the PutItem request. For PutItem, the valid values are:

    • NONE - If ReturnValues is not specified, or if its value is NONE, then nothing is returned. (This setting is the default for ReturnValues.)

    • ALL_OLD - If PutItem overwrote an attribute name-value pair, then the content of the old item is returned.

    The ReturnValues parameter is used by several DynamoDB operations; however, PutItem does not recognize any values other than NONE or ALL_OLD.

  • :return_consumed_capacity (String) —

    Determines the level of detail about provisioned throughput consumption that is returned in the response:

    • INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed.

      Note that some operations, such as GetItem and BatchGetItem, do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).

    • TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.

    • NONE - No ConsumedCapacity details are included in the response.

  • :return_item_collection_metrics (String) —

    Determines whether item collection metrics are returned. If set to SIZE, the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to NONE (the default), no statistics are returned.

  • :conditional_operator (String) —

    This is a legacy parameter. Use ConditionExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.

  • :condition_expression (String) —

    A condition that must be satisfied in order for a conditional PutItem operation to succeed.

    An expression can contain any of the following:

    • Functions: attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size

      These function names are case-sensitive.

    • Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN

    • Logical operators: AND | OR | NOT

    For more information on condition expressions, see Condition Expressions in the Amazon DynamoDB Developer Guide.

  • :expression_attribute_names (Hash<String,String>) —

    One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

    • To access an attribute whose name conflicts with a DynamoDB reserved word.

    • To create a placeholder for repeating occurrences of an attribute name in an expression.

    • To prevent special characters in an attribute name from being misinterpreted in an expression.

    Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

    • Percentile

    ^

    The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

    • `{"#P":"Percentile"}`

    ^

    You could then use this substitution in an expression, as in this example:

    • #P = :val

    ^

    Tokens that begin with the : character are expression attribute values, which are placeholders for the actual value at runtime.

    For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

  • :expression_attribute_values (Hash<String,Types::AttributeValue>) —

    One or more values that can be substituted in an expression.

    Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:

    Available | Backordered | Discontinued

    You would first need to specify ExpressionAttributeValues as follows:

    { ":avail":`{"S":"Available"}`, ":back":`{"S":"Backordered"}`, ":disc":`{"S":"Discontinued"}` }

    You could then use these values in an expression, such as this:

    ProductStatus IN (:avail, :back, :disc)

    For more information on expression attribute values, see Condition Expressions in the Amazon DynamoDB Developer Guide.

Returns:

See Also:

#query(options = {}) ⇒ Types::QueryOutput

The Query operation finds items based on primary key values. You can query any table or secondary index that has a composite primary key (a partition key and a sort key).

Use the KeyConditionExpression parameter to provide a specific value for the partition key. The Query operation will return all of the items from the table or index with that partition key value. You can optionally narrow the scope of the Query operation by specifying a sort key value and a comparison operator in KeyConditionExpression. To further refine the Query results, you can optionally provide a FilterExpression. A FilterExpression determines which items within the results should be returned to you. All of the other results are discarded.

A Query operation always returns a result set. If no matching items are found, the result set will be empty. Queries that do not return results consume the minimum number of read capacity units for that type of read operation.

DynamoDB calculates the number of read capacity units consumed based on item size, not on the amount of data that is returned to an application. The number of capacity units consumed will be the same whether you request all of the attributes (the default behavior) or just some of them (using a projection expression). The number will also be the same whether or not you use a FilterExpression.

Query results are always sorted by the sort key value. If the data type of the sort key is Number, the results are returned in numeric order; otherwise, the results are returned in order of UTF-8 bytes. By default, the sort order is ascending. To reverse the order, set the ScanIndexForward parameter to false.

A single Query operation will read up to the maximum number of items set (if using the Limit parameter) or a maximum of 1 MB of data and then apply any filtering to the results using FilterExpression. If LastEvaluatedKey is present in the response, you will need to paginate the result set. For more information, see Paginating the Results in the Amazon DynamoDB Developer Guide.

FilterExpression is applied after a Query finishes, but before the results are returned. A FilterExpression cannot contain partition key or sort key attributes. You need to specify those attributes in the KeyConditionExpression.

A Query operation can return an empty result set and a LastEvaluatedKey if all the items read for the page of results are filtered out.

You can query a table, a local secondary index, or a global secondary index. For a query on a table or on a local secondary index, you can set the ConsistentRead parameter to true and obtain a strongly consistent result. Global secondary indexes support eventually consistent reads only, so do not specify ConsistentRead when querying a global secondary index.

Examples:

Request syntax example with placeholder values


table.query({
  index_name: "IndexName",
  select: "ALL_ATTRIBUTES", # accepts ALL_ATTRIBUTES, ALL_PROJECTED_ATTRIBUTES, SPECIFIC_ATTRIBUTES, COUNT
  attributes_to_get: ["AttributeName"],
  limit: 1,
  consistent_read: false,
  key_conditions: {
    "AttributeName" => {
      attribute_value_list: ["value"], # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
      comparison_operator: "EQ", # required, accepts EQ, NE, IN, LE, LT, GE, GT, BETWEEN, NOT_NULL, NULL, CONTAINS, NOT_CONTAINS, BEGINS_WITH
    },
  },
  query_filter: {
    "AttributeName" => {
      attribute_value_list: ["value"], # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
      comparison_operator: "EQ", # required, accepts EQ, NE, IN, LE, LT, GE, GT, BETWEEN, NOT_NULL, NULL, CONTAINS, NOT_CONTAINS, BEGINS_WITH
    },
  },
  conditional_operator: "AND", # accepts AND, OR
  scan_index_forward: false,
  exclusive_start_key: {
    "AttributeName" => "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
  },
  return_consumed_capacity: "INDEXES", # accepts INDEXES, TOTAL, NONE
  projection_expression: "ProjectionExpression",
  filter_expression: "ConditionExpression",
  key_condition_expression: "KeyExpression",
  expression_attribute_names: {
    "ExpressionAttributeNameVariable" => "AttributeName",
  },
  expression_attribute_values: {
    "ExpressionAttributeValueVariable" => "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
  },
})

Options Hash (options):

  • :index_name (String) —

    The name of an index to query. This index can be any local secondary index or global secondary index on the table. Note that if you use the IndexName parameter, you must also provide TableName.

  • :select (String) —

    The attributes to be returned in the result. You can retrieve all item attributes, specific item attributes, the count of matching items, or in the case of an index, some or all of the attributes projected into the index.

    • ALL_ATTRIBUTES - Returns all of the item attributes from the specified table or index. If you query a local secondary index, then for each matching item in the index, DynamoDB fetches the entire item from the parent table. If the index is configured to project all item attributes, then all of the data can be obtained from the local secondary index, and no fetching is required.

    • ALL_PROJECTED_ATTRIBUTES - Allowed only when querying an index. Retrieves all attributes that have been projected into the index. If the index is configured to project all attributes, this return value is equivalent to specifying ALL_ATTRIBUTES.

    • COUNT - Returns the number of matching items, rather than the matching items themselves.

    • SPECIFIC_ATTRIBUTES - Returns only the attributes listed in AttributesToGet. This return value is equivalent to specifying AttributesToGet without specifying any value for Select.

      If you query or scan a local secondary index and request only attributes that are projected into that index, the operation will read only the index and not the table. If any of the requested attributes are not projected into the local secondary index, DynamoDB fetches each of these attributes from the parent table. This extra fetching incurs additional throughput cost and latency.

      If you query or scan a global secondary index, you can only request attributes that are projected into the index. Global secondary index queries cannot fetch attributes from the parent table.

    If neither Select nor AttributesToGet are specified, DynamoDB defaults to ALL_ATTRIBUTES when accessing a table, and ALL_PROJECTED_ATTRIBUTES when accessing an index. You cannot use both Select and AttributesToGet together in a single request, unless the value for Select is SPECIFIC_ATTRIBUTES. (This usage is equivalent to specifying AttributesToGet without any value for Select.)

    If you use the ProjectionExpression parameter, then the value for Select can only be SPECIFIC_ATTRIBUTES. Any other value for Select will return an error.

  • :attributes_to_get (Array<String>) —

    This is a legacy parameter. Use ProjectionExpression instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.

  • :limit (Integer) —

    The maximum number of items to evaluate (not necessarily the number of matching items). If DynamoDB processes the number of items up to the limit while processing the results, it stops the operation and returns the matching values up to that point, and a key in LastEvaluatedKey to apply in a subsequent operation, so that you can pick up where you left off. Also, if the processed dataset size exceeds 1 MB before DynamoDB reaches this limit, it stops the operation and returns the matching values up to the limit, and a key in LastEvaluatedKey to apply in a subsequent operation to continue the operation. For more information, see Query and Scan in the Amazon DynamoDB Developer Guide.

  • :consistent_read (Boolean) —

    Determines the read consistency model: If set to true, then the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.

    Strongly consistent reads are not supported on global secondary indexes. If you query a global secondary index with ConsistentRead set to true, you will receive a ValidationException.

  • :key_conditions (Hash<String,Types::Condition>) —

    This is a legacy parameter. Use KeyConditionExpression instead. For more information, see KeyConditions in the Amazon DynamoDB Developer Guide.

  • :query_filter (Hash<String,Types::Condition>) —

    This is a legacy parameter. Use FilterExpression instead. For more information, see QueryFilter in the Amazon DynamoDB Developer Guide.

  • :conditional_operator (String) —

    This is a legacy parameter. Use FilterExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.

  • :scan_index_forward (Boolean) —

    Specifies the order for index traversal: If true (default), the traversal is performed in ascending order; if false, the traversal is performed in descending order.

    Items with the same partition key value are stored in sorted order by sort key. If the sort key data type is Number, the results are stored in numeric order. For type String, the results are stored in order of UTF-8 bytes. For type Binary, DynamoDB treats each byte of the binary data as unsigned.

    If ScanIndexForward is true, DynamoDB returns the results in the order in which they are stored (by sort key value). This is the default behavior. If ScanIndexForward is false, DynamoDB reads the results in reverse order by sort key value, and then returns the results to the client.

  • :exclusive_start_key (Hash<String,Types::AttributeValue>) —

    The primary key of the first item that this operation will evaluate. Use the value that was returned for LastEvaluatedKey in the previous operation.

    The data type for ExclusiveStartKey must be String, Number, or Binary. No set data types are allowed.

  • :return_consumed_capacity (String) —

    Determines the level of detail about provisioned throughput consumption that is returned in the response:

    • INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed.

      Note that some operations, such as GetItem and BatchGetItem, do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).

    • TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.

    • NONE - No ConsumedCapacity details are included in the response.

  • :projection_expression (String) —

    A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.

    If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.

    For more information, see Accessing Item Attributes in the Amazon DynamoDB Developer Guide.

  • :filter_expression (String) —

    A string that contains conditions that DynamoDB applies after the Query operation, but before the data is returned to you. Items that do not satisfy the FilterExpression criteria are not returned.

    A FilterExpression does not allow key attributes. You cannot define a filter expression based on a partition key or a sort key.

    A FilterExpression is applied after the items have already been read; the process of filtering does not consume any additional read capacity units.

    For more information, see Filter Expressions in the Amazon DynamoDB Developer Guide.

  • :key_condition_expression (String) —

    The condition that specifies the key values for items to be retrieved by the Query action.

    The condition must perform an equality test on a single partition key value.

    The condition can optionally perform one of several comparison tests on a single sort key value. This allows Query to retrieve one item with a given partition key value and sort key value, or several items that have the same partition key value but different sort key values.

    The partition key equality test is required, and must be specified in the following format:

    partitionKeyName = :partitionkeyval

    If you also want to provide a condition for the sort key, it must be combined using AND with the condition for the sort key. Following is an example, using the = comparison operator for the sort key:

    partitionKeyName = :partitionkeyval AND sortKeyName = :sortkeyval

    Valid comparisons for the sort key condition are as follows:

    • sortKeyName = :sortkeyval - true if the sort key value is equal to :sortkeyval.

    • sortKeyName < :sortkeyval - true if the sort key value is less than :sortkeyval.

    • sortKeyName <= :sortkeyval - true if the sort key value is less than or equal to :sortkeyval.

    • sortKeyName > :sortkeyval - true if the sort key value is greater than :sortkeyval.

    • sortKeyName >= :sortkeyval - true if the sort key value is greater than or equal to :sortkeyval.

    • sortKeyName BETWEEN :sortkeyval1 AND :sortkeyval2 - true if the sort key value is greater than or equal to :sortkeyval1, and less than or equal to :sortkeyval2.

    • begins_with ( sortKeyName, :sortkeyval ) - true if the sort key value begins with a particular operand. (You cannot use this function with a sort key that is of type Number.) Note that the function name begins_with is case-sensitive.

    Use the ExpressionAttributeValues parameter to replace tokens such as :partitionval and :sortval with actual values at runtime.

    You can optionally use the ExpressionAttributeNames parameter to replace the names of the partition key and sort key with placeholder tokens. This option might be necessary if an attribute name conflicts with a DynamoDB reserved word. For example, the following KeyConditionExpression parameter causes an error because Size is a reserved word:

    • Size = :myval

    ^

    To work around this, define a placeholder (such a #S) to represent the attribute name Size. KeyConditionExpression then is as follows:

    • #S = :myval

    ^

    For a list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide.

    For more information on ExpressionAttributeNames and ExpressionAttributeValues, see Using Placeholders for Attribute Names and Values in the Amazon DynamoDB Developer Guide.

  • :expression_attribute_names (Hash<String,String>) —

    One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

    • To access an attribute whose name conflicts with a DynamoDB reserved word.

    • To create a placeholder for repeating occurrences of an attribute name in an expression.

    • To prevent special characters in an attribute name from being misinterpreted in an expression.

    Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

    • Percentile

    ^

    The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

    • `{"#P":"Percentile"}`

    ^

    You could then use this substitution in an expression, as in this example:

    • #P = :val

    ^

    Tokens that begin with the : character are expression attribute values, which are placeholders for the actual value at runtime.

    For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

  • :expression_attribute_values (Hash<String,Types::AttributeValue>) —

    One or more values that can be substituted in an expression.

    Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:

    Available | Backordered | Discontinued

    You would first need to specify ExpressionAttributeValues as follows:

    { ":avail":`{"S":"Available"}`, ":back":`{"S":"Backordered"}`, ":disc":`{"S":"Discontinued"}` }

    You could then use these values in an expression, such as this:

    ProductStatus IN (:avail, :back, :disc)

    For more information on expression attribute values, see Specifying Conditions in the Amazon DynamoDB Developer Guide.

Returns:

See Also:

#scan(options = {}) ⇒ Types::ScanOutput

The Scan operation returns one or more items and item attributes by accessing every item in a table or a secondary index. To have DynamoDB return fewer items, you can provide a FilterExpression operation.

If the total number of scanned items exceeds the maximum dataset size limit of 1 MB, the scan stops and results are returned to the user as a LastEvaluatedKey value to continue the scan in a subsequent operation. The results also include the number of items exceeding the limit. A scan can result in no table data meeting the filter criteria.

A single Scan operation reads up to the maximum number of items set (if using the Limit parameter) or a maximum of 1 MB of data and then apply any filtering to the results using FilterExpression. If LastEvaluatedKey is present in the response, you need to paginate the result set. For more information, see Paginating the Results in the Amazon DynamoDB Developer Guide.

Scan operations proceed sequentially; however, for faster performance on a large table or secondary index, applications can request a parallel Scan operation by providing the Segment and TotalSegments parameters. For more information, see Parallel Scan in the Amazon DynamoDB Developer Guide.

Scan uses eventually consistent reads when accessing the data in a table; therefore, the result set might not include the changes to data in the table immediately before the operation began. If you need a consistent copy of the data, as of the time that the Scan begins, you can set the ConsistentRead parameter to true.

Examples:

Request syntax example with placeholder values


table.scan({
  index_name: "IndexName",
  attributes_to_get: ["AttributeName"],
  limit: 1,
  select: "ALL_ATTRIBUTES", # accepts ALL_ATTRIBUTES, ALL_PROJECTED_ATTRIBUTES, SPECIFIC_ATTRIBUTES, COUNT
  scan_filter: {
    "AttributeName" => {
      attribute_value_list: ["value"], # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
      comparison_operator: "EQ", # required, accepts EQ, NE, IN, LE, LT, GE, GT, BETWEEN, NOT_NULL, NULL, CONTAINS, NOT_CONTAINS, BEGINS_WITH
    },
  },
  conditional_operator: "AND", # accepts AND, OR
  exclusive_start_key: {
    "AttributeName" => "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
  },
  return_consumed_capacity: "INDEXES", # accepts INDEXES, TOTAL, NONE
  total_segments: 1,
  segment: 1,
  projection_expression: "ProjectionExpression",
  filter_expression: "ConditionExpression",
  expression_attribute_names: {
    "ExpressionAttributeNameVariable" => "AttributeName",
  },
  expression_attribute_values: {
    "ExpressionAttributeValueVariable" => "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
  },
  consistent_read: false,
})

Options Hash (options):

  • :index_name (String) —

    The name of a secondary index to scan. This index can be any local secondary index or global secondary index. Note that if you use the IndexName parameter, you must also provide TableName.

  • :attributes_to_get (Array<String>) —

    This is a legacy parameter. Use ProjectionExpression instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.

  • :limit (Integer) —

    The maximum number of items to evaluate (not necessarily the number of matching items). If DynamoDB processes the number of items up to the limit while processing the results, it stops the operation and returns the matching values up to that point, and a key in LastEvaluatedKey to apply in a subsequent operation, so that you can pick up where you left off. Also, if the processed dataset size exceeds 1 MB before DynamoDB reaches this limit, it stops the operation and returns the matching values up to the limit, and a key in LastEvaluatedKey to apply in a subsequent operation to continue the operation. For more information, see Working with Queries in the Amazon DynamoDB Developer Guide.

  • :select (String) —

    The attributes to be returned in the result. You can retrieve all item attributes, specific item attributes, the count of matching items, or in the case of an index, some or all of the attributes projected into the index.

    • ALL_ATTRIBUTES - Returns all of the item attributes from the specified table or index. If you query a local secondary index, then for each matching item in the index, DynamoDB fetches the entire item from the parent table. If the index is configured to project all item attributes, then all of the data can be obtained from the local secondary index, and no fetching is required.

    • ALL_PROJECTED_ATTRIBUTES - Allowed only when querying an index. Retrieves all attributes that have been projected into the index. If the index is configured to project all attributes, this return value is equivalent to specifying ALL_ATTRIBUTES.

    • COUNT - Returns the number of matching items, rather than the matching items themselves.

    • SPECIFIC_ATTRIBUTES - Returns only the attributes listed in AttributesToGet. This return value is equivalent to specifying AttributesToGet without specifying any value for Select.

      If you query or scan a local secondary index and request only attributes that are projected into that index, the operation reads only the index and not the table. If any of the requested attributes are not projected into the local secondary index, DynamoDB fetches each of these attributes from the parent table. This extra fetching incurs additional throughput cost and latency.

      If you query or scan a global secondary index, you can only request attributes that are projected into the index. Global secondary index queries cannot fetch attributes from the parent table.

    If neither Select nor AttributesToGet are specified, DynamoDB defaults to ALL_ATTRIBUTES when accessing a table, and ALL_PROJECTED_ATTRIBUTES when accessing an index. You cannot use both Select and AttributesToGet together in a single request, unless the value for Select is SPECIFIC_ATTRIBUTES. (This usage is equivalent to specifying AttributesToGet without any value for Select.)

    If you use the ProjectionExpression parameter, then the value for Select can only be SPECIFIC_ATTRIBUTES. Any other value for Select will return an error.

  • :scan_filter (Hash<String,Types::Condition>) —

    This is a legacy parameter. Use FilterExpression instead. For more information, see ScanFilter in the Amazon DynamoDB Developer Guide.

  • :conditional_operator (String) —

    This is a legacy parameter. Use FilterExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.

  • :exclusive_start_key (Hash<String,Types::AttributeValue>) —

    The primary key of the first item that this operation will evaluate. Use the value that was returned for LastEvaluatedKey in the previous operation.

    The data type for ExclusiveStartKey must be String, Number or Binary. No set data types are allowed.

    In a parallel scan, a Scan request that includes ExclusiveStartKey must specify the same segment whose previous Scan returned the corresponding value of LastEvaluatedKey.

  • :return_consumed_capacity (String) —

    Determines the level of detail about provisioned throughput consumption that is returned in the response:

    • INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed.

      Note that some operations, such as GetItem and BatchGetItem, do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).

    • TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.

    • NONE - No ConsumedCapacity details are included in the response.

  • :total_segments (Integer) —

    For a parallel Scan request, TotalSegments represents the total number of segments into which the Scan operation will be divided. The value of TotalSegments corresponds to the number of application workers that will perform the parallel scan. For example, if you want to use four application threads to scan a table or an index, specify a TotalSegments value of 4.

    The value for TotalSegments must be greater than or equal to 1, and less than or equal to 1000000. If you specify a TotalSegments value of 1, the Scan operation will be sequential rather than parallel.

    If you specify TotalSegments, you must also specify Segment.

  • :segment (Integer) —

    For a parallel Scan request, Segment identifies an individual segment to be scanned by an application worker.

    Segment IDs are zero-based, so the first segment is always 0. For example, if you want to use four application threads to scan a table or an index, then the first thread specifies a Segment value of 0, the second thread specifies 1, and so on.

    The value of LastEvaluatedKey returned from a parallel Scan request must be used as ExclusiveStartKey with the same segment ID in a subsequent Scan operation.

    The value for Segment must be greater than or equal to 0, and less than the value provided for TotalSegments.

    If you provide Segment, you must also provide TotalSegments.

  • :projection_expression (String) —

    A string that identifies one or more attributes to retrieve from the specified table or index. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.

    If no attribute names are specified, then all attributes will be returned. If any of the requested attributes are not found, they will not appear in the result.

    For more information, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

  • :filter_expression (String) —

    A string that contains conditions that DynamoDB applies after the Scan operation, but before the data is returned to you. Items that do not satisfy the FilterExpression criteria are not returned.

    A FilterExpression is applied after the items have already been read; the process of filtering does not consume any additional read capacity units.

    For more information, see Filter Expressions in the Amazon DynamoDB Developer Guide.

  • :expression_attribute_names (Hash<String,String>) —

    One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

    • To access an attribute whose name conflicts with a DynamoDB reserved word.

    • To create a placeholder for repeating occurrences of an attribute name in an expression.

    • To prevent special characters in an attribute name from being misinterpreted in an expression.

    Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

    • Percentile

    ^

    The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

    • `{"#P":"Percentile"}`

    ^

    You could then use this substitution in an expression, as in this example:

    • #P = :val

    ^

    Tokens that begin with the : character are expression attribute values, which are placeholders for the actual value at runtime.

    For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

  • :expression_attribute_values (Hash<String,Types::AttributeValue>) —

    One or more values that can be substituted in an expression.

    Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:

    Available | Backordered | Discontinued

    You would first need to specify ExpressionAttributeValues as follows:

    { ":avail":`{"S":"Available"}`, ":back":`{"S":"Backordered"}`, ":disc":`{"S":"Discontinued"}` }

    You could then use these values in an expression, such as this:

    ProductStatus IN (:avail, :back, :disc)

    For more information on expression attribute values, see Condition Expressions in the Amazon DynamoDB Developer Guide.

  • :consistent_read (Boolean) —

    A Boolean value that determines the read consistency model during the scan:

    • If ConsistentRead is false, then the data returned from Scan might not contain the results from other recently completed write operations (PutItem, UpdateItem, or DeleteItem).

    • If ConsistentRead is true, then all of the write operations that completed before the Scan began are guaranteed to be contained in the Scan response.

    The default setting for ConsistentRead is false.

    The ConsistentRead parameter is not supported on global secondary indexes. If you scan a global secondary index with ConsistentRead set to true, you will receive a ValidationException.

Returns:

See Also:

#update(options = {}) ⇒ Table

Examples:

Request syntax example with placeholder values


table.update({
  attribute_definitions: [
    {
      attribute_name: "KeySchemaAttributeName", # required
      attribute_type: "S", # required, accepts S, N, B
    },
  ],
  billing_mode: "PROVISIONED", # accepts PROVISIONED, PAY_PER_REQUEST
  provisioned_throughput: {
    read_capacity_units: 1, # required
    write_capacity_units: 1, # required
  },
  global_secondary_index_updates: [
    {
      update: {
        index_name: "IndexName", # required
        provisioned_throughput: { # required
          read_capacity_units: 1, # required
          write_capacity_units: 1, # required
        },
      },
      create: {
        index_name: "IndexName", # required
        key_schema: [ # required
          {
            attribute_name: "KeySchemaAttributeName", # required
            key_type: "HASH", # required, accepts HASH, RANGE
          },
        ],
        projection: { # required
          projection_type: "ALL", # accepts ALL, KEYS_ONLY, INCLUDE
          non_key_attributes: ["NonKeyAttributeName"],
        },
        provisioned_throughput: {
          read_capacity_units: 1, # required
          write_capacity_units: 1, # required
        },
      },
      delete: {
        index_name: "IndexName", # required
      },
    },
  ],
  stream_specification: {
    stream_enabled: false, # required
    stream_view_type: "NEW_IMAGE", # accepts NEW_IMAGE, OLD_IMAGE, NEW_AND_OLD_IMAGES, KEYS_ONLY
  },
  sse_specification: {
    enabled: false,
    sse_type: "AES256", # accepts AES256, KMS
    kms_master_key_id: "KMSMasterKeyId",
  },
  replica_updates: [
    {
      create: {
        region_name: "RegionName", # required
        kms_master_key_id: "KMSMasterKeyId",
        provisioned_throughput_override: {
          read_capacity_units: 1,
        },
        global_secondary_indexes: [
          {
            index_name: "IndexName", # required
            provisioned_throughput_override: {
              read_capacity_units: 1,
            },
          },
        ],
      },
      update: {
        region_name: "RegionName", # required
        kms_master_key_id: "KMSMasterKeyId",
        provisioned_throughput_override: {
          read_capacity_units: 1,
        },
        global_secondary_indexes: [
          {
            index_name: "IndexName", # required
            provisioned_throughput_override: {
              read_capacity_units: 1,
            },
          },
        ],
      },
      delete: {
        region_name: "RegionName", # required
      },
    },
  ],
})

Basic usage

table = table.update(options)
table.name
#=> "table-name"

Options Hash (options):

  • :attribute_definitions (Array<Types::AttributeDefinition>) —

    An array of attributes that describe the key schema for the table and indexes. If you are adding a new global secondary index to the table, AttributeDefinitions must include the key element(s) of the new index.

  • :billing_mode (String) —

    Controls how you are charged for read and write throughput and how you manage capacity. When switching from pay-per-request to provisioned capacity, initial provisioned capacity values must be set. The initial provisioned capacity values are estimated based on the consumed read and write capacity of your table and global secondary indexes over the past 30 minutes.

    • PROVISIONED - We recommend using PROVISIONED for predictable workloads. PROVISIONED sets the billing mode to Provisioned Mode.

    • PAY_PER_REQUEST - We recommend using PAY_PER_REQUEST for unpredictable workloads. PAY_PER_REQUEST sets the billing mode to On-Demand Mode.

  • :provisioned_throughput (Types::ProvisionedThroughput) —

    The new provisioned throughput settings for the specified table or index.

  • :global_secondary_index_updates (Array<Types::GlobalSecondaryIndexUpdate>) —

    An array of one or more global secondary indexes for the table. For each index in the array, you can request one action:

    • Create - add a new global secondary index to the table.

    • Update - modify the provisioned throughput settings of an existing global secondary index.

    • Delete - remove a global secondary index from the table.

    You can create or delete only one global secondary index per UpdateTable operation.

    For more information, see Managing Global Secondary Indexes in the Amazon DynamoDB Developer Guide.

  • :stream_specification (Types::StreamSpecification) —

    Represents the DynamoDB Streams configuration for the table.

    You receive a ResourceInUseException if you try to enable a stream on a table that already has a stream, or if you try to disable a stream on a table that doesn\'t have a stream.

  • :sse_specification (Types::SSESpecification) —

    The new server-side encryption settings for the specified table.

  • :replica_updates (Array<Types::ReplicationGroupUpdate>) —

    A list of replica update actions (create, delete, or update) for the table.

    This property only applies to Version 2019.11.21 of global tables.

Returns:

See Also:

#update_item(options = {}) ⇒ Types::UpdateItemOutput

Edits an existing item's attributes, or adds a new item to the table if it does not already exist. You can put, delete, or add attribute values. You can also perform a conditional update on an existing item (insert a new attribute name-value pair if it doesn't exist, or replace an existing name-value pair if it has certain expected attribute values).

You can also return the item's attribute values in the same UpdateItem operation using the ReturnValues parameter.

Examples:

Request syntax example with placeholder values


table.update_item({
  key: { # required
    "AttributeName" => "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
  },
  attribute_updates: {
    "AttributeName" => {
      value: "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
      action: "ADD", # accepts ADD, PUT, DELETE
    },
  },
  expected: {
    "AttributeName" => {
      value: "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
      exists: false,
      comparison_operator: "EQ", # accepts EQ, NE, IN, LE, LT, GE, GT, BETWEEN, NOT_NULL, NULL, CONTAINS, NOT_CONTAINS, BEGINS_WITH
      attribute_value_list: ["value"], # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
    },
  },
  conditional_operator: "AND", # accepts AND, OR
  return_values: "NONE", # accepts NONE, ALL_OLD, UPDATED_OLD, ALL_NEW, UPDATED_NEW
  return_consumed_capacity: "INDEXES", # accepts INDEXES, TOTAL, NONE
  return_item_collection_metrics: "SIZE", # accepts SIZE, NONE
  update_expression: "UpdateExpression",
  condition_expression: "ConditionExpression",
  expression_attribute_names: {
    "ExpressionAttributeNameVariable" => "AttributeName",
  },
  expression_attribute_values: {
    "ExpressionAttributeValueVariable" => "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
  },
})

Options Hash (options):

  • :key (required, Hash<String,Types::AttributeValue>) —

    The primary key of the item to be updated. Each element consists of an attribute name and a value for that attribute.

    For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.

  • :attribute_updates (Hash<String,Types::AttributeValueUpdate>) —

    This is a legacy parameter. Use UpdateExpression instead. For more information, see AttributeUpdates in the Amazon DynamoDB Developer Guide.

  • :expected (Hash<String,Types::ExpectedAttributeValue>) —

    This is a legacy parameter. Use ConditionExpression instead. For more information, see Expected in the Amazon DynamoDB Developer Guide.

  • :conditional_operator (String) —

    This is a legacy parameter. Use ConditionExpression instead. For more information, see ConditionalOperator in the Amazon DynamoDB Developer Guide.

  • :return_values (String) —

    Use ReturnValues if you want to get the item attributes as they appear before or after they are updated. For UpdateItem, the valid values are:

    • NONE - If ReturnValues is not specified, or if its value is NONE, then nothing is returned. (This setting is the default for ReturnValues.)

    • ALL_OLD - Returns all of the attributes of the item, as they appeared before the UpdateItem operation.

    • UPDATED_OLD - Returns only the updated attributes, as they appeared before the UpdateItem operation.

    • ALL_NEW - Returns all of the attributes of the item, as they appear after the UpdateItem operation.

    • UPDATED_NEW - Returns only the updated attributes, as they appear after the UpdateItem operation.

    There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.

    The values returned are strongly consistent.

  • :return_consumed_capacity (String) —

    Determines the level of detail about provisioned throughput consumption that is returned in the response:

    • INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed.

      Note that some operations, such as GetItem and BatchGetItem, do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).

    • TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.

    • NONE - No ConsumedCapacity details are included in the response.

  • :return_item_collection_metrics (String) —

    Determines whether item collection metrics are returned. If set to SIZE, the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to NONE (the default), no statistics are returned.

  • :update_expression (String) —

    An expression that defines one or more attributes to be updated, the action to be performed on them, and new values for them.

    The following action values are available for UpdateExpression.

    • SET - Adds one or more attributes and values to an item. If any of these attributes already exist, they are replaced by the new values. You can also use SET to add or subtract from an attribute that is of type Number. For example: SET myNum = myNum + :val

      SET supports the following functions:

      • if_not_exists (path, operand) - if the item does not contain an attribute at the specified path, then if_not_exists evaluates to operand; otherwise, it evaluates to path. You can use this function to avoid overwriting an attribute that may already be present in the item.

      • list_append (operand, operand) - evaluates to a list with a new element added to it. You can append the new element to the start or the end of the list by reversing the order of the operands.

      These function names are case-sensitive.

    • REMOVE - Removes one or more attributes from an item.

    • ADD - Adds the specified value to the item, if the attribute does not already exist. If the attribute does exist, then the behavior of ADD depends on the data type of the attribute:

      • If the existing attribute is a number, and if Value is also a number, then Value is mathematically added to the existing attribute. If Value is a negative number, then it is subtracted from the existing attribute.

        If you use ADD to increment or decrement a number value for an item that doesn\'t exist before the update, DynamoDB uses 0 as the initial value.

        Similarly, if you use ADD for an existing item to increment or decrement an attribute value that doesn\'t exist before the update, DynamoDB uses 0 as the initial value. For example, suppose that the item you want to update doesn\'t have an attribute named itemcount, but you decide to ADD the number 3 to this attribute anyway. DynamoDB will create the itemcount attribute, set its initial value to 0, and finally add 3 to it. The result will be a new itemcount attribute in the item, with a value of 3.

      • If the existing data type is a set and if Value is also a set, then Value is added to the existing set. For example, if the attribute value is the set [1,2], and the ADD action specified [3], then the final attribute value is [1,2,3]. An error occurs if an ADD action is specified for a set attribute and the attribute type specified does not match the existing set type.

        Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, the Value must also be a set of strings.

      The ADD action only supports Number and set data types. In addition, ADD can only be used on top-level attributes, not nested attributes.

    • DELETE - Deletes an element from a set.

      If a set of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set [a,b,c] and the DELETE action specifies [a,c], then the final attribute value is [b]. Specifying an empty set is an error.

      The DELETE action only supports set data types. In addition, DELETE can only be used on top-level attributes, not nested attributes.

    You can have many actions in a single expression, such as the following: SET a=:value1, b=:value2 DELETE :value3, :value4, :value5

    For more information on update expressions, see Modifying Items and Attributes in the Amazon DynamoDB Developer Guide.

  • :condition_expression (String) —

    A condition that must be satisfied in order for a conditional update to succeed.

    An expression can contain any of the following:

    • Functions: attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size

      These function names are case-sensitive.

    • Comparison operators: = | <> | < | > | <= | >= | BETWEEN | IN

    • Logical operators: AND | OR | NOT

    For more information about condition expressions, see Specifying Conditions in the Amazon DynamoDB Developer Guide.

  • :expression_attribute_names (Hash<String,String>) —

    One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

    • To access an attribute whose name conflicts with a DynamoDB reserved word.

    • To create a placeholder for repeating occurrences of an attribute name in an expression.

    • To prevent special characters in an attribute name from being misinterpreted in an expression.

    Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

    • Percentile

    ^

    The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see Reserved Words in the Amazon DynamoDB Developer Guide.) To work around this, you could specify the following for ExpressionAttributeNames:

    • `{"#P":"Percentile"}`

    ^

    You could then use this substitution in an expression, as in this example:

    • #P = :val

    ^

    Tokens that begin with the : character are expression attribute values, which are placeholders for the actual value at runtime.

    For more information about expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

  • :expression_attribute_values (Hash<String,Types::AttributeValue>) —

    One or more values that can be substituted in an expression.

    Use the : (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the ProductStatus attribute was one of the following:

    Available | Backordered | Discontinued

    You would first need to specify ExpressionAttributeValues as follows:

    { ":avail":`{"S":"Available"}`, ":back":`{"S":"Backordered"}`, ":disc":`{"S":"Discontinued"}` }

    You could then use these values in an expression, such as this:

    ProductStatus IN (:avail, :back, :disc)

    For more information on expression attribute values, see Condition Expressions in the Amazon DynamoDB Developer Guide.

Returns:

See Also: