User CRUD API

A simple RESTful API built with Node.js, Express.js, Mongoose, and MongoDB.

This project provides CRUD operations for a User resource. It can be used as a starter guide for developers who want to build REST APIs using Express and MongoDB.

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Features

• Create a new user
• Get all users
• Get a single user by ID
• Update user details
• Delete a user
• Validate required input fields
• Handle duplicate email errors
• Return proper HTTP status codes and messages
• Test API endpoints using Postman

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Tech Stack

• Node.js
• Express.js
• MongoDB
• Mongoose
• dotenv
• Nodemon

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Project Structure

user-crud-api/
│
├── models/
│   └── User.js
│
├── routes/
│   └── userRoutes.js
│
├── .env
├── server.js
├── package.json
└── README.md

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Installation and Setup

1. Clone the Repository

git clone https://github.com/your-username/user-crud-api.git

cd user-crud-api

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2. Install Dependencies

npm install

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3. Create .env File

Create a .env file in the root folder and add the following:

PORT=5000
MONGO_URI=mongodb://127.0.0.1:27017/user_crud_db

For MongoDB Atlas, replace MONGO_URI with your Atlas connection string.

Example:

PORT=5000
MONGO_URI=mongodb+srv://username:password@cluster.mongodb.net/user_crud_db

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4. Run the Project

For development:

npm run dev

For production:

npm start

After running the project, you should see:

MongoDB connected successfully
Server running on port 5000

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API Base URL

http://localhost:5000/api/users

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API Endpoints

Method	Endpoint	Description
POST	/api/users	Create a new user
GET	/api/users	Get all users
GET	/api/users/:id	Get a single user
PUT	/api/users/:id	Update a user
DELETE	/api/users/:id	Delete a user

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User Model

Field	Type	Required	Description
name	String	Yes	User full name
email	String	Yes	User email address
age	Number	Yes	User age
city	String	Yes	User city

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Request and Response Examples

Create User

Method: POST

URL:

http://localhost:5000/api/users

Body:

{
  "name": "John Shepard",
  "email": "john@example.com",
  "age": 24,
  "city": "London"
}

Success Response:

{
  "success": true,
  "message": "User created successfully",
  "data": {
    "_id": "user_id_here",
    "name": "John Shepard",
    "email": "john@example.com",
    "age": 24,
    "city": "London",
    "createdAt": "2026-05-09T10:00:00.000Z",
    "updatedAt": "2026-05-09T10:00:00.000Z"
  }
}

Status Code: 201 Created

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Get All Users

Method: GET

URL:

http://localhost:5000/api/users

Success Response:

{
  "success": true,
  "message": "Users fetched successfully",
  "count": 1,
  "data": [
    {
      "_id": "user_id_here",
      "name": "John Shepard",
      "email": "john@example.com",
      "age": 24,
      "city": "London"
    }
  ]
}

Status Code: 200 OK

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Get Single User

Method: GET

URL:

http://localhost:5000/api/users/user_id_here

Success Response:

{
  "success": true,
  "message": "User fetched successfully",
  "data": {
    "_id": "user_id_here",
    "name": "John Shepard",
    "email": "john@example.com",
    "age": 24,
    "city": "London"
  }
}

Status Code: 200 OK

User Not Found Response:

{
  "success": false,
  "message": "User not found"
}

Status Code: 404 Not Found

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Update User

Method: PUT

URL:

http://localhost:5000/api/users/user_id_here

Body:

{
  "name": "John Updated",
  "age": 25,
  "city": "Manchester"
}

Success Response:

{
  "success": true,
  "message": "User updated successfully",
  "data": {
    "_id": "user_id_here",
    "name": "John Updated",
    "email": "john@example.com",
    "age": 25,
    "city": "Manchester"
  }
}

Status Code: 200 OK

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Delete User

Method: DELETE

URL:

http://localhost:5000/api/users/user_id_here

Success Response:

{
  "success": true,
  "message": "User deleted successfully"
}

Status Code: 200 OK

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Validation Rules

Field	Validation
name	Required, minimum 2 characters
email	Required, unique, valid email format
age	Required, must be greater than 0
city	Required

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Validation Error Example

If required fields are missing:

{}

Response:

{
  "success": false,
  "message": "Validation failed",
  "errors": [
    "Name is required",
    "Email is required",
    "Age is required",
    "City is required"
  ]
}

Status Code: 400 Bad Request

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Duplicate Email Error Example

If the same email already exists:

{
  "success": false,
  "message": "Email already exists"
}

Status Code: 409 Conflict

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Status Codes

Status Code	Meaning
200	Request successful
201	Resource created successfully
400	Bad request or validation error
404	Resource not found
409	Duplicate data conflict
500	Internal server error

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Testing with Postman

You can test this API using Postman.

Steps

1. Open Postman.
2. Select the HTTP method.
3. Enter the API URL.
4. For POST and PUT requests, go to the Body tab.
5. Select raw.
6. Select JSON.
7. Add the request body.
8. Click Send.

Example request body:

{
  "name": "John Shepard",
  "email": "john@example.com",
  "age": 24,
  "city": "London"
}

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Useful Commands

Install dependencies:

npm install

Run development server:

npm run dev

Run production server:

npm start

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Future Improvements

• Add user authentication using JWT
• Add password hashing using bcrypt
• Add pagination
• Add search and filter options
• Add role-based access control
• Add API documentation using Swagger
• Add unit testing

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Author

Vikas Kushwaha

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License

This project is open-source and available for learning and development purposes.