Introduction

MongoDB is the word that is trending at present. From big organizations all the way down to small-scale start-ups, everyone seems to be using it. Thus, this is a platform that needs to be explored. This article will give you a hang of how to use MongoDB. Let us start with Mongo DB basics. This article also provides examples of MongoDB commands which can be used to understand the platform better. The MongoDB commands examples provided will help you quickly set up your MongoDB server. 

  1. What is MongoDB
  2. Features of MongoDB Shell
  3. Configuration
  4. List of MongoDB Commands
  5. MongoDb Commands Cheatsheet
  6. MongoDB database Commands

1. What is MongoDB

MongoDB is a rich document-oriented NoSQL database. It is an open-source relational database management system presented in 2009 with features quite similar to MySQL. However, MongoDB has quite a few additional capabilities and new enhancements, which is the reason for its widespread use and popularity. 

Companies such as Sony, HootSuite, and Zendesk use MongoDb is as their primary resource. MongoDB commands are quite simple to use and understand, even for beginners. However, you have to ensure to follow the MongoDB syntax correctly while executing the MongoDB commands.

Let us go on to explain what is a MongoDB Mongo shell. MongoDB Mongo Shell is a collaborative JavaScript interface that enables one to interact with MongoDB instances using the command line. The MongoDB shell can be used for administrative operations such as maintenance of database instances and data manipulation. MongoDB shell commands are easy to use and understand.

2. Features of MongoDB Shell

Some of the top features of Mongo DB Shell are:

  • It executes all MongoDB queries from the Mongo shell.
  • It manipulates data and performs administration operations.
  • It utilizes JavaScript and a related API to give commands.
  • One can view the previous commands in the mongo shell by using the up and down arrow keys.
  • Error messages can be printed, which helps one know what went wrong with the commands.

3. Configuration

To work with MongoDB, install MongoDB by visiting the official Website of MongoDB and selecting the version specific to your OS. Once you have finished the installation process, navigate to program files and select the MongoDB directory. For example, C: -> Program Files -> MongoDB -> Server -> 5.0(version) -> bin.

In the bin, there are two executable files that are present. They are mongod and mongo. Mongod stands for “Mongo Daemon”, which is the background process used by MongoDB. Mongo is a command-line shell that interacts with the client. To start the server, use the following MongoDB start command:

C:\> mkdir data/dbC:\.

MongoDB needs a folder to accumulate all data. The default data directory path of MongoDB is /data/db. Thus, it is important to provide all the directories.

Next go to the bin and run the mongod command. The MongoDB server is up and running. To work with this server, we require a different mediator. So, open a different command window inside the bin folder and run the mongo command. Once the connection accepted message is displayed, it indicates that the installation is successful. 

4. List of MongoDB Commands

The following is the MongoDB commands list which is most widely used:

  1. Mongo: Use this command to ask the platform to link to the localhost on the default port 27017. 
  2. Mongo <host>/<database>: Use this command to connect the platform to a specific database. For example, mongo 10.121.65.58/mydb.
  3. Mongo –host <hostname or IP address> –port <port no>: Use this command to connect to a remote host using a particular port. For example, mongo –host 10.120.65.23 –port 23021.
  4. Use <database name>: Use this command to switch between databases. For example, use mydb.
  5. Db: Use this command to view the database which is being used. 
  6. Help: Use this command to activate the built-in help window. For example, help
  7. load(<filename>): Use this command to run a JavaScript file. For example, load (myscript.js).
  8. db.help(): Use this command if you need help with Db methods. For example, db.help().

5. MongoDb Commands Cheatsheet

Following are the MongoDB commands which can be used as a cheat sheet to help you get up and running with the platform:

  1. Start and stop the MongoDB Database: sudo service mongod start and sudo service mongod stop.
  2. Access the MongoDB database using Shell: mongo –host localhost:27017
  3. Show all databases: show dbs
  4. To switch to a database: use <db>
  5. Add a collection: db.createCollection(“user”)
  6. Insert a record in the collection; A record is inserted in the collection, “user.” : db.user.insert({“name”: “AS”, “location”: “Bombay”, “username”: “AFK”})
  7. Login into the database with username and password: mongo -u USERNAME -p PASSWORD –authenticationDatabase DATABASENAME.

6. MongoDB database Commands

The MongoDB database commands are used to create, change, and update the database. Some of them are:

  1. db.adminCommand(cmd): This admin command runs against the admin database to run the specified database commands by giving a helper.
  2. db.aggregate(): This aggregate method initializes a particular admin diagnostic pipeline that does not require any underlying collection.
  3. db.cloneDatabase(“hostname”): The clonedatabase method copies the database to the current database.
Note: As MongoDB is non-SQL, one cannot run any MongoDB SQL commands. However, one can run SQL SELECT Query against MongoDB. SQL support comprises expressions, functions, aggregation for collections with arrays and objects.

Conclusion

MongoDB commands are the best practice solution to maintain high availability, efficient and scalable operations, which is today’s business demand.

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