Lambda + API Gateway + DynamoDB example

myfunction.js

'use strict';

console.log('Loading function');

const doc = require('dynamodb-doc');

const dynamo = new doc.DynamoDB();

exports.handler = (event, context, callback) => {
    //console.log('Received event:', JSON.stringify(event, null, 2));

    const done = (err, res) => callback(null, {
        statusCode: err ? '400' : '200',
        body: err ? err.message : JSON.stringify(res),
        headers: {
            'Content-Type': 'application/json',
        },
    });

    switch (event.queryStringParameters.action) {
        case 'delete':
            dynamo.deleteItem({
                TableName: 'mytable', 
                Key: { id: event.queryStringParameters.id } 
            }, done);
            break;
        case 'get':
            dynamo.scan({ 
                TableName: 'mytable' 
            }, done);
            break;
        case 'put':
            dynamo.putItem({ 
                TableName: 'mytable', 
                Item: { 
                    id: event.queryStringParameters.id, 
                    value: event.queryStringParameters.value 
                } }, done);
            break;
        case 'update':
            dynamo.updateItem({ 
                TableName: 'mytable', 
                Item: { 
                    id: event.queryStringParameters.id, 
                    value: event.queryStringParameters.value
                } }, done);
            break;
        default:
            done(new Error(`Unsupported method "${event.queryStringParameters.action}"`));
    }
};