Mongodb Show Collection

In MongoDB, collections store documents, similar to tables in relational databases. This guide explains how to list all collections in a database using MongoDB Shell, Node.js (Mongoose), and Compass.

1. Show Collections Using MongoDB Shell

A. Open MongoDB Shell

Start the MongoDB shell by running:

mongosh

B. Select a Database

Choose the database you want to list collections for:

use blogDB

C. List All Collections

Run the following command:

show collections

✅ Example Output:

posts
users
comments

This displays all collections inside blogDB.

2. Show Collections Using Node.js (Mongoose)

A. Install Mongoose (If Not Installed)

npm install mongoose

B. Create a Script to List Collections

Create listCollections.js:

const mongoose = require('mongoose');

mongoose.connect('mongodb://127.0.0.1:27017/blogDB', {
    useNewUrlParser: true,
    useUnifiedTopology: true
}).then(() => console.log("✅ Connected to MongoDB"))
  .catch(err => console.error("❌ Connection Error:", err));

async function listCollections() {
    try {
        const collections = await mongoose.connection.db.listCollections().toArray();
        console.log("📂 Collections in 'blogDB':");
        collections.forEach(collection => console.log(`- ${collection.name}`));
    } catch (error) {
        console.log("❌ Error listing collections:", error.message);
    } finally {
        mongoose.connection.close();
    }
}

listCollections();

✅ Run the script:

node listCollections.js

✅ Example Output:

📂 Collections in 'blogDB':
- posts
- users
- comments

3. Show Collections Using Express.js API

A. Modify `routes/dbRoutes.js`

const express = require('express');
const router = express.Router();
const mongoose = require('mongoose');

// GET - List all collections
router.get('/collections', async (req, res) => {
    try {
        const collections = await mongoose.connection.db.listCollections().toArray();
        res.json(collections.map(col => col.name));
    } catch (error) {
        res.status(400).json({ message: "❌ Error listing collections", error: error.message });
    }
});

module.exports = router;

B. Test the API (Using cURL or Postman)

curl -X GET http://localhost:3000/api/db/collections

✅ Example Response:

["posts", "users", "comments"]

4. Show Collections Using MongoDB Compass

If you prefer a graphical interface, use MongoDB Compass:

Open MongoDB Compass and connect to your database.
Click on the database name (e.g., blogDB).
You will see a list of all collections in that database.

✅ The collections will be displayed on the screen.

5. Summary

✔ Listed collections using MongoDB Shell (show collections).
✔ Used Mongoose to list collections via a script.
✔ Created an Express.js API to fetch collections dynamically.
✔ Used MongoDB Compass for a GUI-based approach.

6. Next Steps

🔹 Filter collections based on specific criteria.
🔹 Implement authentication to secure database queries.
🔹 Monitor database usage and optimize queries.

Would you like help with database security or query optimization? 🚀

Souy Soeng

Mongodb Show Collection