MongoDB Connection Pattern

🎯 Purpose

Establish a reusable MongoDB connection helper that keeps a single shared client across the backend.

📦 Setup

Create src/DB/connection.js to house the singleton connection logic that the rest of the backend reuses:

import mongoose from 'mongoose';
 
export default class MongoDBConnection {
   static connection;
 
   static async connectIfNot() {
      if (this.connection) {
         return this.connection;
      }
 
      this.connection = await mongoose.connect(process.env.MONGO_DB, {
         useNewUrlParser: true,
         useUnifiedTopology: true,
      });
 
      // Add any database scripts (like ensuring indexes or defaults) here if needed.
 
      return this.connection;
   }
}

🛠️ How It Works

1. Single connection guard – connectIfNot ensures Mongoose initializes once per process. Subsequent calls reuse the same client.
2. Config-driven – All connection details live in environment variables so deployment targets stay configurable.
3. Script hook – Keep database automation in one place by dropping required scripts in the marked comment block.

✅ Usage Tips

• Expose MongoDBConnection.connectIfNot() early in your server bootstrap (API handlers, background jobs, etc.).
• Add the necessary database scripts (for example ensuring indexes or inserting required defaults) inside the comment block so everything runs after the connection is ready.
• Keep credentials and host strings in environment variables rather than hard coding them in the helper.

📎 Environment

Set MONGO_DB in your environment variables (.env or deployment platform) with the MongoDB connection string before calling connectIfNot.