DCL language is used to control access to data in a database.This language defines the access permissions for users and groups on the pieces of data in database.E.g We use commands to provide permissions for individual user to make SELECT statements for data table.

Examples of DCL commands include:

•     GRANT to allow specified users to perform specified tasks.
•     REVOKE to cancel previously granted or denied permissions.

The following privileges can be GRANTED TO or REVOKED FROM a user or role:

DML is used by computer programs database users to retrieve, insert, delete and update data in a database.Currently the most popular data manipulation language is that of SQL, which is used to retrieve and manipulate data in a Relational database.

Basic Data operations are:-

1. Select
2. Insert
3. Update
4. Delete

A Data Definition Language (DDL) is a computer language for defining data structures.In SQL, DDL contains commands for defining structure of data,altering and deleting structure of data.

1. Used to specify a database scheme as a set of definitions expressed in a DDL
2. DDL statements are compiled, resulting in a set of tables stored in a special file called a data dictionary or data directory.

    

    

SQL is a language used for accessing and manipulating databases by issuing queries(commands or request) for data.

basic operations for data base are INSERT,UPDATE,DELETE and SQL provide commands for each of these operations but SQL also provide others type of operations of DATABASES.

SQL can be divided into two parts:

1. Data Manipulation Language (DML)
2. Data Definition Language (DDL).