How to Switch Database in MongoDB: Simple Guide

In MongoDB shell, you switch databases using the use <databaseName> command. In application code, you select a database by calling client.db(<databaseName>) on your MongoDB client instance.

Syntax

To switch databases in the MongoDB shell, use the use command followed by the database name. In application code, use the db() method on the client object to select a database.

• use <databaseName>: Switches to the specified database in the shell.
• client.db(<databaseName>): Returns a database object for the specified database in code.

mongodb

use myDatabase

// In application code (Node.js example):
const db = client.db('myDatabase');

Example

This example shows switching databases in the MongoDB shell and in Node.js code using the official MongoDB driver.

javascript

// MongoDB shell example
use salesDB
show collections

// Node.js example
import { MongoClient } from 'mongodb';

async function run() {
  const client = new MongoClient('mongodb://localhost:27017');
  await client.connect();

  // Switch to 'salesDB' database
  const db = client.db('salesDB');

  // List collections in 'salesDB'
  const collections = await db.listCollections().toArray();
  console.log(collections.map(c => c.name));

  await client.close();
}

run();

Output

[ 'orders', 'customers', 'products' ]

Common Pitfalls

Common mistakes when switching databases include:

• Using use command only works in the MongoDB shell, not in application code.
• Forgetting to call client.db() to get the database object before running queries.
• Assuming switching database changes the client connection; it only changes the context for commands.

javascript

// Wrong: Trying to use 'use' in Node.js code
// This will cause an error
client.use('salesDB');

// Right: Use client.db() method
const db = client.db('salesDB');

Quick Reference

Action	Command / Method	Context
Switch database in shell	use	MongoDB shell
Get database in code	client.db()	Application code (Node.js, Python, etc.)
List collections	db.getCollectionNames() or db.listCollections()	After switching database
Run query	db.collection.find()	On selected database

Key Takeaways

Use use <databaseName> in MongoDB shell to switch databases.

In application code, call client.db(<databaseName>) to select a database.

Switching database does not change the connection, only the context for commands.

Do not use use command in application code; it only works in the shell.

Always get the database object before running queries on collections.