Database Connection in Next.js (with TypeScript)

Prerequisites

1. Next.js (Next.js edge network pe run karta hai - multiple servers like India, USA, etc.).

   • Edge ka matlab hai distributed servers.

   • Next.js ka behavior serverless hota hai, so different requests alag-alag edges pe handle ho sakti hain.

2. Mongoose for database connection.

3. TypeScript for strong typing.

   

   

   Step 1: Install Next.js

   • Open VS Code.

   • Run this command to set up a Next.js project:

       npx create-next-app@latest my-app --typescript
     

Step 2: Create a Utility Folder (lib)

Next.js me, database connection ke liye hum ek utility folder banate hain.

2(a): Create the lib directory

• lib folder isko util ya utility bhi kaha jata hai.

2(b): Create a file named db.ts

This file will manage the MongoDB connection using Mongoose.
Install Mongoose:

    npm install mongoose

Step 3: Writing the db.ts File

Step 4: TypeScript Setup for Global Variables

Since Next.js runs in a serverless environment, global variables are often reset. To avoid TypeScript errors related to mongoose, we define global types.

4(a): Create types.d.ts file

• File location: Root directory (outside any folder).

• File content:

import { Connection } from "mongoose";

declare global {
    var mongoose: {
        conn: Connection | null;
        promise: Promise<Connection> | null;
    };
}

export {};
Step 5: Environment Variables SetupCreate a .env file in the root of your project and add your MongoDB connection string:MONGODB_URI=mongodb+srv://<username>:<password>@cluster.mongodb.net/<dbname>
Replace <username>, <password>, and <dbname> with your database credentials.

Important Notes:

1. bufferCommands in Mongoose:

   • Yeh option temporarily database commands ko store karta hai jab tak connection establish nahi hota.

2. maxPoolSize:

   • Ek samay me kitne active connections maintain honge, iska control deti hai.

Final Thoughts

• Next.js ka edge-based architecture aur serverless model ko dhyan me rakhte hue cached connection kaafi important hoti hai.

• Aapke database connections efficient banane ke liye global variable aur Mongoose options ka sahi use zaroori hai.