In this blog, we'll walk through creating a simple CRUD (Create, Read, Update, Delete) application using Express.js, MongoDB, and Swagger for API documentation. This guide will help you understand the basics of setting up a RESTful API with these technologies.
Prerequisites
Before we start, make sure you have the following installed:
- Node.js and npm (Node Package Manager)
- MongoDB (You can use a local instance or a cloud service like MongoDB Atlas)
Project Setup
- Initialize the Project: Create a new directory for your project and initialize it with npm.
mkdir express-sample-crud
cd express-sample-crud
npm init -y
- Install Dependencies: Install the necessary packages for your project.
npm install express mongoose body-parser cors dotenv swagger-jsdoc swagger-ui-express
Project Structure
Here's a brief overview of the project structure:
express-sample-crud/
│
├── config/
│ ├── db.js
│ └── swagger.js
│
├── controllers/
│ └── userController.js
│
├── models/
│ └── userModel.js
│
├── routes/
│ └── userRoutes.js
│
├── my-express-app/
│ ├── .env
│ └── app.js
│
└── package.json
Step-by-Step Guide
1. Database Configuration
Create a db.js file in the config directory to set up the MongoDB connection.
const mongoose = require("mongoose");
const dotenv = require("dotenv");
dotenv.config();
const connectDB = async () => {
try {
await mongoose.connect(process.env.MONGO_URI, {
useNewUrlParser: true,
useUnifiedTopology: true,
});
console.log("MongoDB connected");
} catch (err) {
console.error(err.message);
process.exit(1);
}
};
module.exports = connectDB;
2. Swagger Configuration
Create a swagger.js file in the config directory to set up Swagger for API documentation.
const swaggerJsdoc = require("swagger-jsdoc");
const swaggerUi = require("swagger-ui-express");
const options = {
definition: {
openapi: "3.0.0",
info: {
title: "My Express API",
version: "1.0.0",
description: "A simple Express API with CRUD operations",
},
servers: [
{
url: "http://localhost:5000",
},
],
},
apis: ["./routes/*.js"],
};
const specs = swaggerJsdoc(options);
module.exports = (app) => {
app.use("/api-docs", swaggerUi.serve, swaggerUi.setup(specs));
};
3. User Model
Create a userModel.js file in the models directory to define the User schema.
const mongoose = require("mongoose");
const UserSchema = new mongoose.Schema({
name: {
type: String,
required: true,
},
email: {
type: String,
required: true,
unique: true,
},
password: {
type: String,
required: true,
},
});
module.exports = mongoose.model("User", UserSchema);
4. User Controller
Create a userController.js file in the controllers directory to handle the CRUD operations.
const User = require("../models/userModel");
exports.getUsers = async (req, res) => {
try {
const users = await User.find();
res.json(users);
} catch (err) {
res.status(500).json({ message: err.message });
}
};
exports.createUser = async (req, res) => {
const { name, email, password } = req.body;
try {
const newUser = new User({ name, email, password });
await newUser.save();
res.status(201).json(newUser);
} catch (err) {
res.status(400).json({ message: err.message });
}
};
exports.updateUser = async (req, res) => {
const { id } = req.params;
const { name, email, password } = req.body;
try {
const user = await User.findByIdAndUpdate(
id,
{ name, email, password },
{ new: true }
);
if (!user) {
return res.status(404).json({ message: "User not found" });
}
res.json(user);
} catch (err) {
res.status(400).json({ message: err.message });
}
};
exports.deleteUser = async (req, res) => {
const { id } = req.params;
try {
const user = await User.findByIdAndDelete(id);
if (!user) {
return res.status(404).json({ message: "User not found" });
}
res.json({ message: "User deleted successfully" });
} catch (err) {
res.status(500).json({ message: err.message });
}
};
5. User Routes
Create a userRoutes.js file in the routes directory to define the API endpoints.
const express = require("express");
const {
getUsers,
createUser,
updateUser,
deleteUser,
} = require("../controllers/userController");
const router = express.Router();
/**
* @swagger
* components:
* schemas:
* User:
* type: object
* required:
* - name
* - email
* - password
* properties:
* name:
* type: string
* description: The user's name
* email:
* type: string
* description: The user's email
* password:
* type: string
* description: The user's password
* example:
* name: John Doe
* email: john.doe@example.com
* password: password123
*/
/**
* @swagger
* /api/users:
* get:
* summary: Get all users
* responses:
* 200:
* description: A list of users
* content:
* application/json:
* schema:
* type: array
* items:
* $ref: '#/components/schemas/User'
*/
router.get("/users", getUsers);
/**
* @swagger
* /api/users:
* post:
* summary: Create a new user
* requestBody:
* required: true
* content:
* application/json:
* schema:
* $ref: '#/components/schemas/User'
* responses:
* 201:
* description: The created user
* content:
* application/json:
* schema:
* $ref: '#/components/schemas/User'
* 400:
* description: Invalid input
*/
router.post("/users", createUser);
/**
* @swagger
* /api/users/{id}:
* put:
* summary: Update a user
* parameters:
* - in: path
* name: id
* schema:
* type: string
* required: true
* description: The user ID
* requestBody:
* required: true
* content:
* application/json:
* schema:
* $ref: '#/components/schemas/User'
* responses:
* 200:
* description: The updated user
* content:
* application/json:
* schema:
* $ref: '#/components/schemas/User'
* 404:
* description: User not found
*/
router.put("/users/:id", updateUser);
/**
* @swagger
* /api/users/{id}:
* delete:
* summary: Delete a user
* parameters:
* - in: path
* name: id
* schema:
* type: string
* required: true
* description: The user ID
* responses:
* 200:
* description: User deleted successfully
* 404:
* description: User not found
*/
router.delete("/users/:id", deleteUser);
module.exports = router;
6. Environment Variables
Create a .env file in the my-express-app directory to store environment variables.
MONGO_URI=mongodb://localhost:27017/express_crud
PORT=5000
7. Main Application File
Create an app.js file in the my-express-app directory to set up the Express application.
const express = require("express");
const bodyParser = require("body-parser");
const cors = require("cors");
const dotenv = require("dotenv");
const connectDB = require("./config/db");
const userRoutes = require("./routes/userRoutes");
const swaggerSetup = require("./config/swagger");
dotenv.config();
const app = express();
// Connect to MongoDB
connectDB();
// Middleware
app.use(bodyParser.json());
app.use(cors());
// Routes
app.use("/api", userRoutes);
// Swagger setup
swaggerSetup(app);
const PORT = process.env.PORT || 5000;
app.listen(PORT, () => console.log(`Server running on port ${PORT}`));
8. Package Configuration
Update your package.json file to include the necessary scripts and dependencies.
{
"name": "express-sample-crud",
"version": "1.0.0",
"main": "index.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [],
"author": "",
"license": "ISC",
"description": "",
"dependencies": {
"body-parser": "^1.20.3",
"cors": "^2.8.5",
"dotenv": "^16.4.7",
"express": "^4.21.2",
"mongoose": "^8.11.0",
"swagger-jsdoc": "^6.2.8",
"swagger-ui-express": "^5.0.1"
}
}
Running the Application
- Start your MongoDB server.
- Run the application using the following command:
node app.js
- Open your browser and navigate to
http://localhost:5000/api-docsto view the Swagger API documentation.
Conclusion
You've successfully created a CRUD application using Express.js, MongoDB, and Swagger. This setup provides a solid foundation for building more complex applications.
Don't forget to follow me on GitHub for more projects and updates: My GitHub Profile
You can find the source code for this project on GitHub: Express + MongoDB + Swagger CRUD Sample
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