Most Common MongoDB Commands for MongoDB Beginners [2023]

Logging with MongoDB

The following command applies to logging in with MongoDB.

Note: Users must have the right credentials and database name for access.

Create a Database and Selecting the Database to work with 

In MongoDB, the ‘use’ command is the first step to create a new database. 

Syntax:

On execution, this command will create a new database for a specific name. In case there is a database with a specific name, then it will return with the existing database.

The same ‘use’ command is also used for selecting a database and start working with.  

Example:

Suppose you are starting a new education project with the database ‘edudb’. Then the command would be:

Read: MongoDB Real World Use Cases: Advantages & Top Companies

Check Current Database

You can also check the current database with the command db as:

You need to have at least one file or document in the database to show in the overall list. You can do this by using the insert command easily.

Syntax:

Show all current databases

You can use the following commands to check the present database with show dbs as:

In MongoDB, the test is present as the default database. All the collections by default are stored in the test only. 

You can use the MongoDB command interface to manage tasks related to non-CRUD operations. The interface empowers users to fetch precise information from the server, replicating current scenarios, and run specific map-reduce tasks.

There are also specific commands to run in the current and admin database.

For current database in MondDB, use the following db.runCommand():

For admin database, use the following db.adminCommand():

For Creating a Collection, the following command:

 For inserting a document in the Collection:

Explore Our Software Development Free Courses

To Save and Update document

Here ‘save’ command can do both functions insert an entirely new document or update an existing document.

Note: If there is a matching document ID, then it updates; otherwise, a new document is then created.

 Listing the Users, Roles, and Collections

These commands list the number of users, their roles, and collections.

To Display Collection records 

Explore our Popular Software Engineering Courses

 For Administrative Commands

This command allows information about collection details with total size, storage, and multiple statistics.

 For logging out from the database:

There are different types of commands that you can use in MongoDB, starting with:

User commands

Database Operations

1. User Commands

Aggregation Commands

 Geospatial Commands

 Query and Write operations commands

Query Plan Cache Commands 

upGrad’s Exclusive Software Development Webinar for you –

SAAS Business – What is So Different?

2. Database Operations

Authentication Problems

User Management Commands

Role Management Commands

 Replication Commands

 Sharding Commands

 Session Commands

 Administrative Commands

 Free Monitoring Commands

 Auditing Commands

Command Responses

On every command execution, MongoDB retrieves a response with a specific field:

Checkout: CRUD Operations in MongoDB

In-Demand Software Development Skills

Text Search

To look for particular words or phrases within a collection, utilise text search. The text search command is as follows:

Geospatial Queries

Data searches based on location are done via geospatial queries. The geospatial queries $near and $geoWithin are supported by Mongo shell. The following is the command for geographical queries:

Aggregation

Data within a collection can be subjected to operations like grouping, counting, and averaging using an aggregate. The aggregate command is as follows:

Database and Collection Operations

The creation, modification, and deletion of databases and collections are handled through database and collection operations. The following commands are used to create a collection in MongoDB and database operations:

Array Operators

When working with arrays in a collection, array operators are used. Several array operators, including $push, $pop, and $pull, are supported by MongoDB. The following are the commands for array operators:

Aggregation Framework

Data within a collection can be subjected to complicated operations using the Aggregation Framework, such as merging different collections and grouping data. The Aggregation Framework command is as follows:

Indexing

The performance of queries on a collection is enhanced by indexing. MongoDB supports a variety of index types, including single field, compound, and text indexes. These are the indexing commands:

Map-Reduce

The Map-Reduce algorithm processes large amounts of data inside a collection to get aggregated results. Here is the Map-Reduce command:

Update Operators

Use update operators to modify a collection’s data. MongoDB supports a number of update operators, including $set, $inc, and $push. The update operator commands are as follows:

db.collection_name.update({ condition }, { $set: { field: new_value } }) db.collection_name.update({ condition }, { $inc: { field: increment_value } }) db.collection_name.update({ condition }, { $push: { field: value_to_add } })

What Next?

If you are interested to know more about Big Data, check out our Advanced Certificate Programme in Big Data from IIIT Bangalore.

Read our Popular Articles related to Software Development

Learn Software Development Courses online from the World’s top Universities. Earn Executive PG Programs, Advanced Certificate Programs or Masters Programs to fast-track your career.