MongoDB: The NoSQL Database

Created to lessen your drop table nightmares.#

Does the name refer to mangoes?

No, the ‘Mongo’ is short for ‘humongous’ and ‘DB’ is pretty self-explanatory that it stands for ‘Database’.

What’s NoSQL?

NoSQL is a type of database which generally uses JSON Objects, instead of traditional SQL table system.

Which language it’s written in?

It’s written in C++.

What type of Database Management System does MongoDB follow?

It follows the Relational Database Management System (RDBMS).

Why MongoDB?#

MongoDB is:#

  • Schema-less.

  • It’s customizable.

  • Deep query-ability. MongoDB supports dynamic queries on documents using a document-based query language that’s nearly as powerful as SQL.

  • Scalable.

Name someone whose already bearing it?#

Seems interesting, how do I start using it?

Installation:#

Windows#

  • Go here and download the required setup for your system.

  • Now extract your downloaded file to C:\ drive or any other location. Make sure the name of the extracted folder is mongodb-win32-i386-[version] or mongodb-win32-x86_64-[version]. Here [version] is the version of MongoDB download.

  • Next, open the command prompt and type the following command in

    move mongodb-win64-* mongodb

then,

    C:\>md data
    C:\md data\db
  • Navigate to the bin directory found in the installation folder, set the default DB folder.
    D:\set up\mongodb\bin>mongod.exe --dbpath "d:\set up\mongodb\data"

It’s done!

Ubuntu/Linux#

  • To get the MongoDB public GPG key,
    sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10
  • Create a mongodb.list,
    echo 'deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen' 
       | sudo tee /etc/apt/sources.list.d/mongodb.list
  • Next, to update the repositories use. sudo apt-get update

  • Install MongoDB via apt-get intall mongo-10gen = 2.2.3

Fingertip commands:#

Start: sudo service mongodb start

Stop: sudo service mongodb stop

Restart: sudo service mongodb restart

Help: db.help()

Basic Operations#

Creating a database:#

use DATABASE_NAME
  • The command is used to create or use an existing database.

Check the current database#

db
  • The command is used to know with which database we’re currently interacting.

List Databases#

show dbs
  • The command is used to list databases.

Note: Empty Databases aren’t shown in the list.

Insert data in the database#

db.insert([Raw JSON/JSON file])
  • Suppose JSON file is named as ‘dt.json’, then the function will be used as, db.insert(dt.json)

Query Data#

db.COLLECTION.find()
  • The method is used to find documents in a database, it shows the document in an unstructured way. You may go here to study more about queries in MongoDB

Formatted Data#

db.COLLECTION.find().pretty()
  • The command is used to show data in a formatted way.

Update Data#

db.COLLECTION_NAME.update(SELECTION_CRITERIA, UPDATED_DATA)
  • The command is used to Update the original data with another data or any addition to it.

Drop database#

db.dropDatabase()
  • The command is used to drop the currently selected database.

© Aayushman Choudhary 2021