In this post, you will learn about MongoDB commands, which could get you started and perform minimum database related activities such as create, update, and drop a collection (table). These commands are ideally meant for MongoDB beginners and could be taken as a cheat sheet. You may want to bookmark this page for quick reference.

MongoDB Commands Cheatsheet

The following is the list of the commands:

Start and stop the MongoDB Database:

sudo service mongod start
sudo service mongod stop

Access the MongoDB database using Shell:

mongo --host localhost:27017

Show all databases:

show dbs

Create a database, say, testdb; Switch to the database:

use testdb

Until a collection is created in a database, the database name is not listed as a result of execution of the command, "show dbs."

Add a collection:

db.createCollection("user")

Show all collections in a database; Execute the "use dbname" command to access the database before executing the command given below.

show collections
show tables

The following command also work:

db.getCollectionNames()

Insert a record in the collection; A record is inserted in the collection, "user."

db.user.insert({"name": "Ajitesh Shukla", "location": "hyderabad", "username": "eajitesh"})

Display list of records of a collection; "user" collection is used.

db.user.find()
db.user.find().pretty()

Display a list of records matching with value (s) of specific fields:

db.user.find({"username": "eajitesh"})
db.user.find({"username": "eajitesh", "location": "hyderabad"})

Drop the collection:

db.user.drop()

Create users in the database; The below command creates a user with username as "ajitesh" and having the role such as "readWrite" and "dbAdmin"

db.createUser({"user": "ajitesh", "pwd": "gurukul", "roles": ["readWrite", "dbAdmin"]})

Show users; If executed without selecting a database, it displays all users along with database information.

show users

Login into the database with username and password:

mongo -u USERNAME -p PASSWORD --authenticationDatabase DATABASENAME

For user created in above command, the login command would look like the following:

mongo -u ajitesh -p gurukul --authenticationDatabase testdb

References

MongoDB Shell Quick Reference

Summary

In this post, you learned about the MongoDB cheatsheet commands (especially, helpful for beginners), which could help you quickly get started with MongoDB.

Did you find this article useful? Do you have any questions or suggestions about this article? Leave a comment and ask your questions and I shall do my best to address your queries.