DBMS Languages


DBMS Languages

* Data Manipulation language(DML)
* Data Definition Language(DDL)
* Data Control Language(DCL)
* Transaction Control Language(TCL)

Data Definition Language (DDL)

A data definition language or data description language (DDL) is a syntax similar to a computer programming language for defining data structures, especially database schemas.
For  DBA and database designers
 to specify the conceptual schema
 also used to define internal and external schemas (views). 
In some DBMSs, separate storage definition language (SDL) and view definition language (VDL) are used to define internal and external schemas.

Used to create and modify database objects

Data Manipulation Language (DML):

A data manipulation language (DML) is a family of syntax elements similar to a computer programming language used for inserting, deleting and updating data in a database. Performing read-only queries of data is sometimes also considered a component of DML.

 DML commands  can be embedded in a general-purpose programming language  (host language), such as COBOL, C, Java or an Assembly Language.

 Alternatively, stand-alone DML commands can be applied directly (query  language).

Used to create, modify and retrieve data

Data Control Language

* A data control language (DCL) is a syntax similar to a computer programming language used to control access to data stored in a database. In particular, it is a component of Structured Query Language (SQL).
* Examples of DCL commands include:
* GRANT to allow specified users to perform specified tasks.
* REVOKE to cancel previously granted or denied permissions.

Transaction Control Language

Transaction Control Language (TCL) - Transaction control commands manage changes made by DML commands. These SQL commands are used for managing changes affecting the data. These commands are COMMIT, ROLLBACK, and SAVEPOINT.

About Us

Higher National Diploma in Information Technology

We support for success your future

© copyright hndit.com