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The Amazon SDK for JavaScript V3 API Reference Guide describes in detail all the API operations for the Amazon SDK for JavaScript version 3 (V3).

Creating and using tables in DynamoDB

This Node.js code example shows:

The scenario

Similar to other database systems, DynamoDB stores data in tables. A DynamoDB table is a collection of data that's organized into items that are analogous to rows. To store or access data in DynamoDB, you create and work with tables.

In this example, you use a series of Node.js modules to perform basic operations with a DynamoDB table. The code uses the SDK for JavaScript to create and work with tables by using these methods of the DynamoDB client class:

Prerequisite tasks

To set up and run this example, first complete these tasks:

Creating a table

Create a Node.js module with the file name create-table.js. Be sure to configure the SDK as previously shown, including downloading the required clients and packages. To access DynamoDB, create a DynamoDB client service object. Create a JSON object containing the parameters needed to create a table, which in this example includes the name and data type for each attribute, the key schema, the name of the table, and the units of throughput to provision. Call the CreateTableCommand method of the DynamoDB service object.

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",
      },
    ],
    ProvisionedThroughput: {
      ReadCapacityUnits: 1,
      WriteCapacityUnits: 1,
    },
  });

  const response = await client.send(command);
  console.log(response);
  return response;
};

To run the example, enter the following at the command prompt.

node create-table.js 

This example code can be found here on GitHub.

Listing your tables

Create a Node.js module with the file name list-tables.js. Be sure to configure the SDK as previously shown, including downloading the required clients and packages. To access DynamoDB, create a DynamoDB client service object. Create a JSON object containing the parameters needed to list your tables, which in this example limits the number of tables listed to 10. Call the ListTablesCommand method of the DynamoDB service object.

import { ListTablesCommand, DynamoDBClient } from "@aws-sdk/client-dynamodb";

const client = new DynamoDBClient({});

export const main = async () => {
  const command = new ListTablesCommand({});

  const response = await client.send(command);
  console.log(response);
  return response;
};

To run the example, enter the following at the command prompt.

node list-tables.js 

This example code can be found here on GitHub.

Describing a table

Create a Node.js module with the file name describe-table.js. Be sure to configure the SDK as previously shown, including downloading the required clients and packages. To access DynamoDB, create a DynamoDB client service object. Create a JSON object containing the parameters needed to describe a DescribeTableCommand method of the DynamoDB service object.

import { DescribeTableCommand, DynamoDBClient } from "@aws-sdk/client-dynamodb";

const client = new DynamoDBClient({});

export const main = async () => {
  const command = new DescribeTableCommand({
    TableName: "Pastries",
  });

  const response = await client.send(command);
  console.log(`TABLE NAME: ${response.Table.TableName}`);
  console.log(`TABLE ITEM COUNT: ${response.Table.ItemCount}`);
  return response;
};

To run the example, enter the following at the command prompt.

node describe-table.js 

This example code can be found here on GitHub.

Deleting a table

Create a Node.js module with the file name delete-table.js. Be sure to configure the SDK as previously shown, including downloading the required clients and packages. To access DynamoDB, create a DynamoDB client service object. Create a JSON object containing the parameters needed to delete a table, which in this example includes the name of the table provided as a command-line parameter. Call the DeleteTableCommand method of the DynamoDB service object.

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;
};

To run the example, enter the following at the command prompt.

node delete-table.js 

This example code can be found here on GitHub.