Using the MongoDB Command-Line Interface (CLI)

Introduction

The MongoDB Command-Line Interface (CLI) provides a powerful way to interact with your MongoDB databases. This guide covers the basics of using the MongoDB CLI, including connecting to a database, performing CRUD operations, and managing your MongoDB deployment.

Connecting to MongoDB

Step 1: Start the MongoDB Server

Ensure that the MongoDB server is running on your local machine or remote server:

sudo systemctl start mongod

Step 2: Open the MongoDB Shell

Open a terminal and start the MongoDB shell by running the following command:

mongo

This command connects to the MongoDB server running on the default host (localhost) and port (27017).

Basic Commands

Show Databases

To list all databases on the MongoDB server, use the following command:

show dbs

Switch Database

To switch to a specific database, use the use command:

use myDatabase

Show Collections

To list all collections in the current database, use the following command:

show collections

CRUD Operations

Create

To insert a document into a collection, use the insertOne method:

db.myCollection.insertOne({ name: "John Doe", age: 30, email: "john.doe@example.com" })

Read

To find documents in a collection, use the find method:

db.myCollection.find({ name: "John Doe" })

Update

To update a document in a collection, use the updateOne method:

db.myCollection.updateOne({ name: "John Doe" }, { $set: { age: 31 } })

Delete

To delete a document from a collection, use the deleteOne method:

db.myCollection.deleteOne({ name: "John Doe" })

Database Management

Create a Database

To create a new database, switch to the database and insert a document into a collection:

use newDatabase
db.newCollection.insertOne({ name: "Example" })

Drop a Database

To drop a database, switch to the database and use the dropDatabase method:

use myDatabase
db.dropDatabase()

Drop a Collection

To drop a collection, use the drop method:

db.myCollection.drop()

Conclusion

The MongoDB CLI provides a versatile and efficient way to interact with your MongoDB databases. By mastering the basic commands and CRUD operations, you can effectively manage your MongoDB deployment and perform a wide range of tasks from the command line.