TypeScript and MongoDB

TypeScript is a statically-typed language that is a superset of JavaScript. MongoDB, on the other hand, is a popular NoSQL database that stores data in a document-oriented manner. In this tutorial, we'll explore how to use TypeScript with MongoDB and build a simple CRUD (Create, Read, Update, Delete) application.

Prerequisites

To follow along with this tutorial, you should have basic knowledge of TypeScript, Node.js, and MongoDB.

Step 1: Set up a TypeScript project

First, we need to set up a TypeScript project. Create a new directory for your project and run the following command to initialize a new Node.js project:

npm init -y

Next, install TypeScript as a development dependency:

npm install --save-dev typescript

Create a new file named tsconfig.json in the root of your project directory and add the following configuration:

{
  "compilerOptions": {
    "target": "es6",
    "module": "commonjs",
    "outDir": "dist",
    "strict": true,
    "esModuleInterop": true
  },
  "include": [
    "src/**/*.ts"
  ],
  "exclude": [
    "node_modules"
  ]
}

This configuration sets the target version of ECMAScript to ES6, enables strict type-checking, and specifies an output directory for the compiled TypeScript code.

Step 2: Install dependencies

Next, we need to install the required dependencies for our project. Install the mongodb and @types/mongodb packages:

npm install mongodb @types/mongodb

Step 3: Connect to MongoDB

In this step, we'll establish a connection to MongoDB. Create a new file named index.ts in the src directory and add the following code:

import { MongoClient } from 'mongodb';

const url = 'mongodb://localhost:27017';
const dbName = 'myproject';

MongoClient.connect(url, (err, client) => {
  if (err) {
    console.error(err);
    return;
  }

  const db = client.db(dbName);

  console.log(`Connected to MongoDB at ${url}`);
});

This code connects to a MongoDB instance running on the local machine and logs a message to the console if the connection is successful.

Step 4: Perform CRUD operations

In this step, we'll perform CRUD operations on our MongoDB database. Add the following code to the index.ts file:

import { MongoClient, ObjectId } from 'mongodb';

const url = 'mongodb://localhost:27017';
const dbName = 'myproject';

interface User {
  _id: ObjectId;
  name: string;
  email: string;
}

MongoClient.connect(url, async (err, client) => {
  if (err) {
    console.error(err);
    return;
  }

  const db = client.db(dbName);

  // Create a new user
  const newUser: User = {
    name: 'John Doe',
    email: 'john.doe@example.com'
  };
  const result = await db.collection('users').insertOne(newUser);
  console.log(`New user created with ID: ${result.insertedId}`);

  // Find all users
  const users = await db.collection('users').find().toArray();
  console.log(`Found ${users.length} users`);

  // Update a user
  const userToUpdate = users[0];
  userToUpdate.name = 'Jane Doe';
  const updateResult = await db.collection('users').updateOne(
    { _id: userToUpdate._id },
    { $set: { name: user.name } }
);
console.log(Updated ${updateResult.modifiedCount} user);

// Delete a user
const deleteResult = await db.collection('users').deleteOne({ _id: userToUpdate._id });
console.log(Deleted ${deleteResult.deletedCount} user);

client.close();
});

This code creates a new `User` interface that represents a document in our MongoDB collection. We then create a new user, find all users, update a user, and delete a user.

Step 5: Compile and run the TypeScript code

Finally, we need to compile the TypeScript code and run it. Add the following script to the `package.json` file:

{
  "scripts": {
    "start": "tsc && node dist/index.js"
  }
}

This script runs the TypeScript compiler and then executes the compiled JavaScript code.

Run the following command to start the application:

npm start

You should see the following output in the console:

Connected to MongoDB at mongodb://localhost:27017
New user created with ID: 60997028e38f2d0f1b43d429
Found 1 users
Updated 1 user
Deleted 1 user

Congratulations! You have successfully built a simple CRUD application using TypeScript and MongoDB.

Conclusion

In this tutorial, we learned how to set up a TypeScript project, connect to MongoDB, and perform CRUD operations on the database. TypeScript provides type-checking and improved code readability, making it a great choice for building Node.js applications that interact with MongoDB.