DynamoDB Database Cheatsheet

DynamoDB is a fully managed NoSQL database service provided by Amazon Web Services (AWS). It’s known for its seamless scalability, low-latency performance, and flexibility. Whether you’re a beginner or an experienced developer, having a cheatsheet can be invaluable for quickly referencing essential commands and operations. In this cheatsheet, we’ll cover some of the fundamental DynamoDB concepts and commands.

1. Table Operations

Creating a Table

import boto3

dynamodb = boto3.resource('dynamodb')
table = dynamodb.create_table(
    TableName='YourTableName',
    KeySchema=[
        {'AttributeName': 'PartitionKey', 'KeyType': 'HASH'},
        {'AttributeName': 'SortKey', 'KeyType': 'RANGE'}
    ],
    AttributeDefinitions=[
        {'AttributeName': 'PartitionKey', 'AttributeType': 'S'},
        {'AttributeName': 'SortKey', 'AttributeType': 'N'}
    ],
    ProvisionedThroughput={
        'ReadCapacityUnits': 5,
        'WriteCapacityUnits': 5
    }
)
table.wait_until_exists()

Deleting a Table

table = dynamodb.Table('YourTableName')
table.delete()
table.wait_until_not_exists()

2. Item Operations

Putting an Item

table.put_item(
    Item={
        'PartitionKey': 'Value1',
        'SortKey': 123,
        'Attribute1': 'AttributeValue1',
        'Attribute2': 'AttributeValue2'
    }
)

Getting an Item

response = table.get_item(
    Key={
        'PartitionKey': 'Value1',
        'SortKey': 123
    }
)
item = response.get('Item', {})

Updating an Item

table.update_item(
    Key={
        'PartitionKey': 'Value1',
        'SortKey': 123
    },
    UpdateExpression='SET Attribute1 = :value1',
    ExpressionAttributeValues={
        ':value1': 'NewValue1'
    }
)

Deleting an Item

table.delete_item(
    Key={
        'PartitionKey': 'Value1',
        'SortKey': 123
    }
)

3. Query and Scan Operations

Querying Items

response = table.query(
    KeyConditionExpression=Key('PartitionKey').eq('Value1')
)
items = response.get('Items', [])

Scanning Items

response = table.scan(
    FilterExpression=Attr('Attribute1').begins_with('Prefix')
)
items = response.get('Items', [])

4. Index Operations

Creating an Index

table.update(
    AttributeDefinitions=[
        {'AttributeName': 'NewAttribute', 'AttributeType': 'S'}
    ],
    GlobalSecondaryIndexUpdates=[
        {
            'Create': {
                'IndexName': 'NewIndex',
                'KeySchema': [
                    {'AttributeName': 'NewAttribute', 'KeyType': 'HASH'}
                ],
                'Projection': {'ProjectionType': 'ALL'},
                'ProvisionedThroughput': {
                    'ReadCapacityUnits': 5,
                    'WriteCapacityUnits': 5
                }
            }
        }
    ]
)

Querying Using an Index

response = table.query(
    IndexName='NewIndex',
    KeyConditionExpression=Key('NewAttribute').eq('Value1')
)
items = response.get('Items', [])

This DynamoDB cheatsheet provides a quick reference for essential operations, allowing you to work efficiently with DynamoDB in your applications. Whether you’re creating tables, manipulating items, or querying with indexes, these snippets should serve as a handy guide for your DynamoDB development journey. Remember to adapt these examples to your specific use case and always refer to the official DynamoDB documentation for comprehensive details.

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