Function update_data

samples/sample_app.py:336–375

Demonstrate UpdateItem with update expressions.

(client)

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def update_data(client) -> None:
    """Demonstrate UpdateItem with update expressions."""
    section("Step 5: Update Data (UpdateItem)")

    # Update a user's age and add a new attribute
    client.update_item(
        TableName=USERS_TABLE,
        Key={"userId": {"S": "user-001"}},
        UpdateExpression="SET age = :newage, verified = :v",
        ExpressionAttributeValues={
            ":newage": {"N": "31"},
            ":v": {"BOOL": True},
        },
    )
    print("  ✓ Updated user-001: age=31, verified=true")

    # Update an order status with a condition
    client.update_item(
        TableName=ORDERS_TABLE,
        Key={
            "customerId": {"S": "user-001"},
            "orderId": {"S": "ord-103"},
        },
        UpdateExpression="SET #s = :newstatus",
        ConditionExpression="#s = :oldstatus",
        ExpressionAttributeNames={"#s": "status"},
        ExpressionAttributeValues={
            ":newstatus": {"S": "shipped"},
            ":oldstatus": {"S": "pending"},
        },
    )
    print("  ✓ Updated ord-103: pending → shipped (conditional)")

    # Verify the updates
    resp = client.get_item(
        TableName=USERS_TABLE,
        Key={"userId": {"S": "user-001"}},
    )
    item = resp["Item"]
    print(f"  Verified user-001: age={item['age']['N']}, verified={item['verified']['BOOL']}")
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# Step 6: Batch operations
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