18.md

18. Problem: Express Route with MongoDB Query

Problem Statement: Create an Express route that retrieves all users from the MongoDB database and returns them as a JSON response.

Function Signature:

/**
 * Express route to get all users from MongoDB
 * @param {Object} req - Express request object
 * @param {Object} res - Express response object
 */
function getAllUsers(req, res) {
  // Your implementation here
}

Expected Output:

• Return a JSON response with an array of user objects.

Test Cases:

1. Access the route /users and check if the response contains the expected user data.

Hint:

Import Required Modules: Import the necessary modules, such as express, mongoose, and any other modules required for your application.

Define User Model: If you haven't already, define a User schema and create a User model using Mongoose.

Connect to MongoDB: Use Mongoose to connect to your MongoDB database. Ensure that the connection is established before defining your route.

Create Express Route: Define an Express route using app.get() that listens for requests to /users.

Implement Route Handler: In the route handler function (getAllUsers), use the User.find() method to retrieve all users from the database. Handle any errors that occur during the query.

Return JSON Response: If the query is successful, send a JSON response containing the array of user objects. If there is an error, send an appropriate error response.

Start Express Server: Finally, start your Express server and listen on a specific port (e.g., 3000).