Mongo DB

What is MongoDB..... ?

• open source

• cross platform

• document oriented

• leading NoSql database 

• written in C++

UBUNTU INSTALLATION

•  Download the MongoDB binary file of the latest technology from the site

        https://www.mongodb.org/downloads

• Extrace the file from the downloaded archive using the command 

  tar -zxvf mongodb-linux-x86_64-3.2.4.tgz

•   Copy your extracted archive to the installation directory(target directory)

• Give the location of the MOngoDB installation folder to the PATH variable in bashrc. Add below to the .bashrc file

     export PATH=<mongodb-install-directory>/bin:$PATH

  GETTING STRATED

• navigate to the installation folder
• go to bin folder in it and type  

           ./mongod --dbpath /data/db

• take another terminal and type 

          ./mongo
 
 MongoDB configuration file => etc/mongos.conf

 

Important Terminology 

•  Database  

                       Its a container for collections. Multiple databases resides in   a single MongoDB server.

• Collection 

                       Group of documents is a collection.Typically documents in a collection are  similar. But documents within a collection can have different fields.

• Document

                    Set of key-value pairs. Documents have dynamic schema

• Dynamic Schema 

                     documents in the same collection can have different fields or structure. These documents can have the same field, but values need not to be same. Below shows a sample document structure.

      

 Relationship of RDBMS terminology with MongoDB 

Working with MongoDB

 Below mind-map shows the basic commands when dealing with MongoDB like creating a database, creating a collection, querying  a document etc.

querying a document

    We learnt find() method is used to query a document and find().pretty() to get the display in a formatted way. Below is a screen shot of a simple query

Below shows commands in querying a document on the basis of some condition.
 (in below commands 'mycol' is the collection name)

(hope the update on the following sub topics)

Indexing

Aggregation

Replication

Sharding