How to create a database in MongoDB

Quick Answer

There is no create command. Switch to the new name with use, then write something to it:

use shop
db.createCollection('orders')   // the database now exists

Inserting a document works too: db.orders.insertOne({ item: 'pen' }) creates the database and the collection in one step.

Why use alone does not create anything

use shop only changes which database the shell sends commands to. Nothing is written to the server, so the database doesn't show up anywhere yet:

use shop          // switched to db shop
show dbs          // shop is not listed

db.createCollection('orders')
show dbs          // shop    8.00 KiB

MongoDB creates a database the first time something is stored in it, and removes it when its last collection is dropped. That's why a database you "created" earlier can vanish if you never inserted anything.

Two ways to create it

use shop

// with options: a collection that rejects documents without an email
db.createCollection('customers', {
  validator: { $jsonSchema: { required: ['email'] } }
})

For more on validators, see our guide to MongoDB JSON schema validation.

Create a database without switching to it

In a script you can stay where you are and get a handle to any database with db.getSiblingDB():

db.getSiblingDB('analytics').createCollection('events')

From a terminal, put the database name in the connection string and pass the command with --eval:

mongosh "mongodb://localhost:27017/shop" --eval "db.createCollection('orders')"

From Node.js

client.db('shop') returns a handle without touching the server. The database appears when you write:

import { MongoClient } from 'mongodb'

const client = new MongoClient(process.env.MONGODB_URI)
await client.connect()

const db = client.db('shop')                 // nothing created yet
await db.createCollection('orders')          // now shop exists

await client.close()

From Python (PyMongo)

from pymongo import MongoClient

client = MongoClient("mongodb://localhost:27017")
db = client["shop"]                    # lazy, nothing created yet
db["orders"].insert_one({"item": "pen"})

print("shop" in client.list_database_names())   # True

use my.db
// MongoshInvalidInputError: [COMMON-10001] Invalid database name: my.db

db.getSiblingDB('price$').t.insertOne({})
// MongoServerError: Invalid namespace: price$.t

db.getSiblingDB('a'.repeat(64)).t.insertOne({})
// MongoServerError: db name must be at most 63 characters, found: 64

// with "Shop" already on the server:
db.getSiblingDB('shop').t.insertOne({})
// MongoServerError: db already exists with different case already have: [Shop] trying to create [shop]

Naming rules

• Names can't contain /, \, ., ", $, spaces or a null character, and can be at most 63 characters long.
• Names are case-sensitive, but two databases that differ only by case can't coexist (error code 13297, shown above).
• Don't use admin, config or local. Those are system databases.

Frequently Asked Questions

Is there a CREATE DATABASE command in MongoDB?

No. A database is created automatically the first time you create a collection or insert a document in it.

Why does my new database not show in show dbs?

It has no collections yet. use only switches context. Create a collection or insert a document and it will appear.

How do I create a user for the new database?

Switch to it with use and run db.createUser() with a role such as readWrite on that database. See the create user guide for the full syntax.

How do I create a database in MongoDB Atlas?

In the Atlas UI, open Browse Collections and choose Create Database, which asks for a first collection name. From mongosh connected to Atlas, the same use and createCollection steps work.

Related Guides

• Show databases
• Create a user
• Drop a database