Showing posts with label DQL. Show all posts
Showing posts with label DQL. Show all posts

Saturday, January 3, 2015

What is SQL

Structured English Query Language(SEQUEL) or SQL 

A  language, which has to be used to communicate with a relational database. Sql are controlled by Sql Group. Sql categorized into 5 sub languages.

DDL(Data Definition Language):

This language work with structure of object that are present in database(means tables,procedure,function,view and many more). DDl commands are:

Create , Alter ,Drop,Truncate

DML(Data Manipulation Language):

This language work with the data present in database. DML commands are:
Insert, Update, Delete

DQL(Data Query Language):

This language work with retrieving the data that is present in database. DQL commands  is:

Select

DCL(Data Control Language):

This language work with security of objects  that are present in database. DCL  commands are:
Grant,Revork,Deny

TCL(Transaction Control Language):

This language work with that transaction management. TCL commands are:

Commit, Rollback,Save