node-red-contrib-dynamodb-variable

A Node-RED node for interacting with AWS DynamoDB.

Developed by Andrii Lototskyi

📌 Install

Run the following command in the root directory of your Node-RED installation:

npm install node-red-contrib-dynamodb-variable

This module allows performing CRUD operations and table management on DynamoDB using Node-RED.

📌 Set AWS Credentials

Before using this module, configure AWS credentials inside the DynamoDB Config Node in Node-RED:

• AWS Access Key ID
• AWS Secret Access Key
• AWS Region (e.g., us-east-1)

These credentials are required for authentication with AWS DynamoDB.

Credential Sources

All connection parameters support multiple input types:

• String: Direct value stored securely in Node-RED credentials
• Flow Context: Retrieved from flow context variables
• Global Context: Retrieved from global context variables
• Environment Variable: Retrieved from environment variables

📌 Available Operations

The DynamoDB Node supports the following operations:

1️⃣ Create a Table (createTable)
2️⃣ Get an item (getItem)
3️⃣ Put an item (putItem)
4️⃣ Update an item (updateItem)
5️⃣ Delete an item (deleteItem)
6️⃣ Scan a table (scan)
7️⃣ Query a table (query)

Each operation is selected in the DynamoDB Node via the dropdown menu.

📌 Example Usage in Node-RED

1️⃣ Create a new DynamoDB Table

You can create a table with Primary Key, Sort Key (optional), and Global Secondary Index (GSI).

msg.payload = {
    "tableName": "Transactions",
    "keySchema": [
        { "AttributeName": "userId", "KeyType": "HASH" },
        { "AttributeName": "createdAt", "KeyType": "RANGE" }
    ],
    "attributeDefinitions": [
        { "AttributeName": "userId", "AttributeType": "S" },
        { "AttributeName": "createdAt", "AttributeType": "N" }
    ],
    "billingMode": "PAY_PER_REQUEST" // OR "PROVISIONED"
};
return msg;

2️⃣ Get an item from DynamoDB

msg.payload = {
    "tableName": "Users",
    "key": { "userId": "12345" }
};
return msg;

3️⃣ Put an item into DynamoDB

msg.payload = {
    "tableName": "Users",
    "data": {
        "userId": "12345",
        "name": "John Doe",
        "email": "[email protected]"
    }
};
return msg;

4️⃣ Update an item in DynamoDB

msg.payload = {
    "tableName": "Users",
    "key": { "userId": "12345" },
    "updateExpression": "SET email = :email",
    "expressionValues": { ":email": "[email protected]" }
};
return msg;

5️⃣ Delete an item from DynamoDB

msg.payload = {
    "tableName": "Users",
    "key": { "userId": "12345" }
};
return msg;

6️⃣ Scan a DynamoDB table

msg.payload = {
    "tableName": "Users",
    "filterExpression": "contains(name, :namePart)",
    "expressionValues": { ":namePart": "John" }
};
return msg;

7️⃣ Query a DynamoDB table (with Sort Key and GSI support)

msg.payload = {
    "tableName": "Transactions",
    "indexName": "TransactionIndex",
    "keyConditionExpression": "userId = :userId AND createdAt >= :startDate",
    "expressionValues": {
        ":userId": "user_123",
        ":startDate": 1700000000
    },
    "projectionExpression": "userId, amount, createdAt"
};
return msg;

☝ This will retrieve all transactions for user_123, filtering those created after timestamp 1700000000.

📌 Features & Improvements

✅ Supports all CRUD operations in DynamoDB
✅ Table creation with HASH key, RANGE key, and GSI support
✅ Billing Mode (PAY_PER_REQUEST or PROVISIONED) is configurable
✅ AWS SDK v3 with @aws-sdk/lib-dynamodb for automatic data conversion
✅ Projection and filter expressions for more optimized queries
✅ Supports Global Secondary Index (GSI) and Sorting
✅ Configured directly via Node-RED UI (no settings.js required)
✅ Easy to configure and extend

📌 Support & Issues

If you find any issues, please report them at:
GitHub Issues

📌 Author & License

• Author: Andrii Lototskyi
• License: ISC
• Repository: GitHub

🚀 Happy coding with Node-RED & AWS DynamoDB! 🎉