DynamoDB Data Model Tables

Syntax

To create a table in DynamoDB, use the following syntax:

aws dynamodb create-table --table-name TABLE_NAME --attribute-definitions ATTRIBUTE_DEFINITIONS --key-schema KEY_SCHEMA --provisioned-throughput PROVISIONED_THROUGHPUT

Where:

• TABLE_NAME is the name of the table you want to create.
• ATTRIBUTE_DEFINITIONS is a list of attribute definitions for the table.
• KEY_SCHEMA is a list of key schema elements for the table.
• PROVISIONED_THROUGHPUT is the provisioned throughput for the table.

Example

Here's an example of creating a users table in DynamoDB with a userId attribute as the primary key:

aws dynamodb create-table --table-name users --attribute-definitions AttributeName=userId,AttributeType=S --key-schema AttributeName=userId,KeyType=HASH --provisioned-throughput ReadCapacityUnits=5,WriteCapacityUnits=5

Output

The above command will output the following if successful:

{
    "TableDescription": {
        "AttributeDefinitions": [
            {
                "AttributeName": "userId",
                "AttributeType": "S"
            }
        ],
        "TableName": "users",
        "KeySchema": [
            {
                "AttributeName": "userId",
                "KeyType": "HASH"
            }
        ],
        "TableStatus": "CREATING",
        "CreationDateTime": "2021-10-05T06:18:57.543000+00:00",
        "ProvisionedThroughput": {
            "NumberOfDecreasesToday": 0,
            "ReadCapacityUnits": 5,
            "WriteCapacityUnits": 5
        },
        "TableSizeBytes": 0,
        "ItemCount": 0,
        "TableArn": "arn:aws:dynamodb:us-east-1:xxxxxxxxxxxx:table/users",
        "LocalSecondaryIndexes": [],
        "GlobalSecondaryIndexes": []
    }
}

Explanation

The above example creates a users table with userId as the primary key. The AttributeDefinitions specifies the userId attribute is of type S (string). The KeySchema specifies that userId is the HASH key type, which means it's the primary key for the table. The ProvisionedThroughput specifies the amount of read and write capacity required for the table.

Use

Tables in DynamoDB are used to store data that can be accessed using the primary key or secondary indexes. You can also create Global Secondary Indexes (GSIs) and Local Secondary Indexes (LSIs) to allow querying the table using non-primary key attributes.

Important Points

• Each table in DynamoDB must have a primary key, which can be either a partition key or a composite partition-sort key.
• DynamoDB supports two types of indexes: Global Secondary Indexes (GSIs) and Local Secondary Indexes (LSIs).
• Tables in DynamoDB have provisioned throughput, which specifies the amount of read and write capacity to allocate to the table.
• DynamoDB is a NoSQL database and does not require a fixed schema.

Summary

DynamoDB Data Model Tables is used to create tables to store data in DynamoDB. Tables must have a primary key, and provisioned throughput must be allocated to the table. DynamoDB supports Global Secondary Indexes and Local Secondary Indexes to allow querying using non-primary key attributes.