Lambda Functions with Nodejs CRUD with DynamoDB

LambdaNodeCrud.js

/* Here, there are GET, POST, PUT and DELETE implementations for Lambda functions with Nodejs CRUD using Dynamo DB.
Before the implementation using API Gateway, I used a passed parameter. This implementations are commented */


// GET doesn't change if we are using API Gateway

'use strict';

const AWS = require('aws-sdk'); // Load the AWS SDK for Node.js

exports.handler = async (event, context) => {
    const documentClient = new AWS.DynamoDB.DocumentClient();

    let responseBody = "";
    let statusCode = 0;

    const params = {
        TableName: "Products"
    };

    try {
        const data = await documentClient.scan(params).promise();
        responseBody = JSON.stringify(data.Items);
        statusCode = 200;
    } catch (err) {
        responseBody = `Unable to get Products: ${err}`;
        statusCode = 403;
    }

    const response = {
        statusCode: statusCode,
        headers: {
            "Content-Type": "application/json"
        },
        body: responseBody
    };

    return response;
};

// HardCoded DELETE
'use strict';

const AWS = require('aws-sdk'); // Load the AWS SDK for Node.js

exports.handler = async (event, context) => {
    const documentClient = new AWS.DynamoDB.DocumentClient();

    let responseBody = "";
    let statusCode = 0;

    const params = {
        TableName: "Products",
        Key: {
            id: '12345'
        }
    };

    try {
        const data = await documentClient.delete(params).promise();
        responseBody = JSON.stringify(data);
        statusCode = 204;
    } catch (err) {
        responseBody = `Unable to delete Product: ${err}`;
        statusCode = 403;
    }

    const response = {
        statusCode: statusCode,
        headers: {
            "Content-Type": "application/json"
        },
        body: responseBody
    };

    return response;
};

// Hardcoded PUT (post)
'use strict';

const AWS = require('aws-sdk'); // Load the AWS SDK for Node.js

exports.handler = async (event, context) => {
    const documentClient = new AWS.DynamoDB.DocumentClient();

    let responseBody = "";
    let statusCode = 0;

    const params = {
        TableName: "Products",
        Item: {
            id: '12345',
            productName: "Solar Panels"
        }
    };

    try {
        const data = await documentClient.put(params).promise();
        responseBody = JSON.stringify(data);
        statusCode = 201;
    } catch (err) {
        responseBody = `Unable to put Product: ${err}`;
        statusCode = 403;
    }

    const response = {
        statusCode: statusCode,
        headers: {
            "Content-Type": "application/json"
        },
        body: responseBody
    };

    return response;
};

// Hardcoded UPDATE (put)
'use strict';

const AWS = require('aws-sdk'); // Load the AWS SDK for Node.js

exports.handler = async (event, context) => {
    const documentClient = new AWS.DynamoDB.DocumentClient();

    let responseBody = "";
    let statusCode = 0;

    const params = {
        TableName: "Products",
        Key: {
            id: '12345'
        },
        UpdateExpression: "set productName = :n",
        ExpressionAttributeValues: {
            ":n": "Water pumps"
        },
        ReturnValues: "UPDATED_NEW"
    };

    try {
        const data = await documentClient.update(params).promise();
        responseBody = JSON.stringify(data);
        statusCode = 204;
    } catch (err) {
        responseBody = `Unable to update Product: ${err}`;
        statusCode = 403;
    }

    const response = {
        statusCode: statusCode,
        headers: {
            "Content-Type": "application/json"
        },
        body: responseBody
    };

    return response;
};

/* -------------- */

/* Now, using API Gateway. It uses event parameter */

// PUT (post)
'use strict';

const AWS = require('aws-sdk'); // Load the AWS SDK for Node.js

exports.handler = async (event, context) => {
    const documentClient = new AWS.DynamoDB.DocumentClient();

    let responseBody = "";
    let statusCode = 0;

    const { id, productName } = JSON.parse(event.body);

    const params = {
        TableName: "Products",
        Item: {
            id: id,
            productName: productName
        }
    };

    try {
        const data = await documentClient.put(params).promise();
        responseBody = JSON.stringify(data);
        statusCode = 201;
    } catch (err) {
        responseBody = `Unable to put Product: ${err}`;
        statusCode = 403;
    }

    const response = {
        statusCode: statusCode,
        headers: {
            "Content-Type": "application/json"
        },
        body: responseBody
    };

    return response;
};

// UPDATE (put)'use strict';

const AWS = require('aws-sdk'); // Load the AWS SDK for Node.js

exports.handler = async (event, context) => {
    const documentClient = new AWS.DynamoDB.DocumentClient();

    let responseBody = "";
    let statusCode = 0;

    const { id, productName } = JSON.parse(event.body);

    const params = {
        TableName: "Products",
        Key: {
            id: id
        },
        UpdateExpression: "set productName = :n",
        ExpressionAttributeValues: {
            ":n": productName
        },
        ReturnValues: "UPDATED_NEW"
    };

    try {
        const data = await documentClient.update(params).promise();
        responseBody = JSON.stringify(data);
        statusCode = 204;
    } catch (err) {
        responseBody = `Unable to update Product: ${err}`;
        statusCode = 403;
    }

    const response = {
        statusCode: statusCode,
        headers: {
            "Content-Type": "application/json"
        },
        body: responseBody
    };

    return response;
};

// DELETE
'use strict';

const AWS = require('aws-sdk'); // Load the AWS SDK for Node.js

exports.handler = async (event, context) => {
    const documentClient = new AWS.DynamoDB.DocumentClient();

    let responseBody = "";
    let statusCode = 0;

    const { id } = event.pathParameters;

    const params = {
        TableName: "Products",
        Key: {
            id: id
        }
    };

    try {
        const data = await documentClient.delete(params).promise();
        responseBody = JSON.stringify(data);
        statusCode = 204;
    } catch (err) {
        responseBody = `Unable to delete Product: ${err}`;
        statusCode = 403;
    }

    const response = {
        statusCode: statusCode,
        headers: {
            "Content-Type": "application/json"
        },
        body: responseBody
    };

    return response;
};