Types of SQL Statements

The SQL statements can be categorized into four different categories depending upon there usage.

1)  Data Manupulation Language (DML)

Description - DML statements are usaeful for retrieval of dat from the database tables , enters new rows , change rows, and remove unwanted rows from tables in the database.

Examples of  Data Manupulation Language (DML)

·                     SELECT

·                     INSERT

·                     UPDATE

·                     DELETE

·                    MERGE

2) Data Definition Language(DDL)

Description -DDL statements are used to create , remove , change  database schema objects.

Examples of Data Definition Language(DDL)

·                     CREATE

·                     ALTER

·                     DROP

·                     TRUNCATE

·                     RENAME

·                    COMMENT

3) Data Control Language(DCL)

Description: DCL statements are used to control access to the database schema objects and database itself.

Examples of  Data Control Language(DCL)

·                     GRANT

·                    REVOKE

4) Transaction Control (TCL)

Description : These statements used to manage the changes made by DML statements. 

Changes to the data can be grouped together into logical transaction.

Examples of Transaction Control (TCL)

·                     COMMIT

·                     ROLLBACK

·                     SAVEPOINT