SQL COMMANDS

• SQL commands are instructions, coded into SQL statements, which are used to communicate with the database to perform specific tasks, work, functions and queries with data. 

• SQL commands can be used not only for searching the database but also to perform various other functions like, for example, you can create table, add data to tables, or modify data, drop the table, set permissions for users. SQL commands are grouped into four major categories depending on their functionality:        

There are four types of sqlcommands ,that are 

tsql     1.DDL(DATA DEFINITION LANGUAGE)
           2.DML(DATA MANIPULATION LANGUAGE)
           3.DCL(DATA CONTROL LANGUAGE)
Trans   4.TCL(TRANSACTION CONTROL LANGUAGE)

1.DATA DEFINITION LANGUAGE(DDL):