[DATABASE - MONGO] Introduction to MongoDB

I. Introduction

• MongoDB is an open source NoSQL database management, designed to store a large scale of data and allows to work with data efficiently. (high performance, high availability and easy scalability)
• MongoDB is written in C++.
• It uses collections and documents to store data instead of using tables like traditional relational databases.
• Data is stored in json format called bson.
• MongoDB allows users to save nested documents.

1. Database

• Database is a physical container for collections.
• A MongoDB server can have multiple databases.

2. Collection

• A collection is a set of MongoDB documents, it is the equivalent of an RDBMS table.
• Collections do not enforce a schema which means documents in the same collection can have different fields.
• Documents in the same collection have the related purpose.

3. Documents

• Document is a set of key-value pairs.
• It has flexible schema (they dont need to have the same sets of fields or structure).
• Documents' common field can hold different data types.

4. Example of document

{ _id: ObjectId(7df78ad8902c) name: 'Vivian', gender: 'female', abilities: ['reading', 'speaking', 'eating'], friends: [ { name:'Ann', gender: 'female', }, { user:'Irene', gender: 'female', } ]
}

5. Comparision of RDBMS and MongoDB structure

RDBMS	MongoBD
Database	Database
Table	Collection
Row	Field
Table Join	Embedded documents
Primary key	default key _id auto-created by MongoDB

II. Installation & setup

• Go to MongoDB Download Center to download the current version available of MongoDB.

• Open the msi file when the download is completed and click next button.

• Accept the End-USer License and click next.

• Click complete.

• Copy link of Data Directory and click next.

• Click next then install MongoDB and wait for the process to complete.

• Click finish to complete installation process.

• Go to path C:\Program Files\MongoDB\Server\your-version\bin where MongoDB installed and copy this path.

• Create an environment variable.

  • open system properties > select environment variables
  • choose Path and click Edit
  • Click New > Paste the copied path > OK.

• Open C drive and create folder data and its sub folder db then open command prompt and run mongod command. If data is shown, that means the MongoDB run successfully.