Wednesday, April 16, 2014

MongoDB NoSQL Database/Document Database


MongoDB is open source document database and its NoSQL database. MongoDB implemented in C++.

Now a day’s NoSQL database become popular in the market.

We have two types of Databases
  1. SQL database
  2. NoSQL Database

SQL database

We already know about SQL databases in the market these are RDMS databases. We have many popular RDMS databases in the market such as Oracel, MySQL, DB2, PostgreSQL and SQL Server. RDMS databases are managed the data by using Tables. We store the data in tables.

To communicate with these RDMS databases we have common language called SQL. We will use SQL to access and insert data into tables. We have different relations and its mappings between tables to simplify the complex data storage.

Each database vendor have to provide different clients to connect to different applications and which are developed by different languages. Database vendor is responsible to provide language depended database drivers to connect to other applications with database.

We are talking here about java technology so all database vendors have to provide the java JDBC Driver library with these libraries we can connect to RDBMS databases.

NoSQL Database

NoSQL is one of the concepts to access database without any specific database dependent queries instead of that we will use simple programming based object accessing over the databases.

A NoSQL database provides a mechanism for storage and retrieval of data that employs less constrained consistency models than traditional relational databases. Motivations for this approach include simplicity of design, horizontal scaling and finer control over availability

We have many flavors in NoSQL databases

The following are some of the important types

Document databases

Document databases pair each key with a complex data structure known as a document. Documents can contain many different key-value pairs, or key-array pairs, or even nested documents.

Graph stores

Graph stores are used to store information about networks, such as social connections. Graph stores include Neo4J and HyperGraphDB.

Key-value stores

Key-value stores are the simplest NoSQL databases. Every single item in the database is stored as an attribute name (or "key"), together with its value. Examples of key-value stores are Riak and Voldemort. Some key-value stores, such as Redis, allow each value to have a type, such as "integer", which adds functionality.

Wide-column stores

Wide-column stores such as Cassandra and HBase are optimized for queries over large datasets, and store columns of data together, instead of rows.

More Information


MongoDB is one of the NoSQL database and it is document database.

Working with MongoDB

MongoDB database we can install in any Operating System and we can connect to database server and manage the data.

Install and Using MongoDB

The following are steps
  1. Download MongoDB Database
  2. Create MongoDB data Store Directory
  3. Create MongoDB log file
  4. Create MongoDB configuration file
  5. Start MongoDB server
  6. Connect and use MongoDB

Download MongoDB Database

MongoDB server available for all major operating system bases on our operating system we need to download MongoDB database server

The following is MongoDB server Download location

Windows 7

We have installation files and binary distribution, we can use any thing.


In this article we will install and using MongoDB for Windows 7 and 64 bit OS
Once we download the MongoDB binary distribution ZIP file we will place any one of the directory and need to extract the zip file.

Once you extract we can see bin directory there we can see many .exe file to perform different actions.

Assume we have extracted MongoDB Zip file in D:\MongoDB

The following is screen to show bin directory and exe files of MongoDB

Create MongoDB data Store Directory

We need create one directory there MongoDB will store data.

Assume we have created data directory in D:\MongoDB\data\db

Create MongoDB log file

We also need to create log file for MongoDB to store log information. We need create mongo.log file in any of the directory

Assume we have created mongo.log in D:\MongoDB\log directory.

Create MongoDB configuration file

MongoDB need one configuration file when server starts so we need to create mongo.config file in any location in your machine.
In the configuration file we need to mention data storage path for MongoDB and need to specify the log file location.

We already created data store directory and log file in previous steps.

Create mongo.config file and add following configuration in the file

##store data here
dbpath= D:\MongoDB\data\db

##all output go here

##log read and write operations

The following is sample mongo.config fine one of the directory

The following is screen shot which show required directories for MongoDB server

Important Direcory and files paths as for above assumptions

MongoDB Server Path


MongoDB Server Bin directory Path


MongoDB data store path


MongoDB configuration file path


MongoDB log file path


Start MongoDB server

We have done all the steps and now we will start the MongoDB server

The flowing is command to start server

mongod --config d:\MongoDB\config\mongo.config --dbpath D:\MongoDB\data\db

--config  is MongoDB configuration path

--dbpath  is data store path for MongoDB

Now open windows command prompt and go to MongoDB server bin directory (D:\MongoDB\mongodb-win32-x86_64-2008plus-2.6.0\bin) then run above command in command prompt.

The following screen shot to start MongoDB server

Connect and use MongoDB

Now we already started MongoDB server now we will connect to server.

Following command to connect to MongoDB server


Now open another command prompt and go to bin directory of MongoDB server then enter above command now you can see MongoDB shell to interact with server

The following is screen to show connecting to MongoDB server


When we connect to server it will show connecting to test database.

Interacting with MongoDB server

The following are important commands to interact with MongoDB

show dbs                   : List all databases.
use db_name            : Switches to the database.
show collections    : List all tables in the current selected database.

The following screen to show databases in MongoDB server

Switch to other database


When we switch to database if database already existed it will switch to that database if not then it will be create new database with that name.

So MongoDB wont throws error even database not existed simply it will create same thing we can apply for table.

Display All Tables for Selected Database

Create Table and Store Data

In MongoDB when we store data, if the table not existed then it will create and insert data.
If available then it will store in existed table that we specifies.

The following is command insert data in table



We will use key value pair to represent Colum and its value
In the above users is table and username and gender its columns and values meera , male respectively.

The following screen to insert data in user table

Update Record
db.users.update ({username:"meeraprince",gender:"male"})

List all records from table “users”

Find records where username is “meera”

Find records where username’s length is less than or equal to 4

Delete Record

Reference Links


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