MongoDB Shell List

Introduction

MongoDB is a popular NoSQL database that provides high scalability, performance, and flexibility. The MongoDB shell is a command-line interface that enables developers to interact with the database and perform various operations like query, insert, update, delete, and more. In this article, we will explore some useful MongoDB shell commands that every developer should know.

List of commands

Show databases

To see a list of all the databases in your MongoDB server, use the show databases command as follows:

show databases;

This command will return a list of all the databases available in the server.

Use a database

To use a specific database, run the use command followed by the name of the database:

use myDatabase

This command will use the myDatabase database and return a message that confirms this.

Show collections

Once you have selected a database, you can view the collections within this database using the show collections command:

show collections

This command will show all the collections inside the selected database.

Insert document

To insert a new document into a collection, use the following command:

db.collectionName.insert({key:value, key:value});

Replace collectionName with the name of the collection you want to add to, and key:value with the data you want to add.

Find document

To find an existing document within a collection, use the find command followed by a document filter:

db.collectionName.find({key:value});

Replace collectionName with the name of the collection you want to search in, and key:value with the data you want to find.

Update document

To update an existing document within a collection, use the update command followed by a document filter and the new document data:

db.collectionName.update({key:value}, {$set:{key:newValue}});

Replace collectionName with the name of the collection you want to update, key:value with the data you want to update, and key:newValue with the new data.

Remove document

To remove an existing document within a collection, use the remove command followed by a document filter:

db.collectionName.remove({key:value});

Replace collectionName with the name of the collection you want to remove from and key:value with the data you want to remove.

Aggregate data

To perform data aggregation on a collection, use the aggregate command:

db.collectionName.aggregate({$group:{_id:key, value:{$sum:1}}});

Replace collectionName with the name of the collection you want to aggregate, key with the data you want to group by, and value with the operation you want to perform on the data.

Create index

To create an index on a collection, use the createIndex command:

db.collectionName.createIndex({key:1});

Replace collectionName with the name of the collection you want to create an index on and key with the data you want to create an index for.

Drop index

To drop an existing index on a collection, use the dropIndex command:

db.collectionName.dropIndex({key:1});

Replace collectionName with the name of the collection you want to drop an index on and key with the data you want to remove the index for.

Backup and restore

To backup and restore a MongoDB database, use the mongodump and mongorestore commands respectively:

mongodump --db myDatabase
mongorestore --db myDatabase dump/myDatabase

Replace myDatabase with the name of the database you want to backup and restore.

Conclusion

In this article, we have covered some useful MongoDB shell commands that can help you interact with your database and perform various operations. These commands are just a few examples of the many available commands. By using the MongoDB shell, developers can manage their databases with ease and efficiency.