4 TYPE OF SQL Language

DDL

DDL is short name of Data Definition Language,which deals with database schemas and descriptions, of how the data should reside in the database.

CREATE– to create database and its objects like (table, index, views, store procedure, function and triggers)

ALTER – alters the structure of the existing database

DROP – delete objects from the database

TRUNCATE – remove all records from a table, including all spaces allocated for the records are removed

COMMENT – add comments to the data dictionary

RENAME – rename an object

DML

DML is short name of Data Manipulation Languagewhich deals with data manipulation, and includes most common SQL statements such SELECT, INSERT, UPDATE, DELETE etc, and it is used to store, modify, retrieve, delete and update data in database.

SELECT– retrieve data from the a database

INSERT– insert data into a table

UPDATE– updates existing data within a table

DELETE– Delete all records from a database table

MERGE – UPSERT operation (insert or update)

CALL – call a PL/SQL or Java subprogram

EXPLAIN PLAN – interpretation of the data access path

LOCK TABLE – concurrency Control

DCL

DCL is short name of Data Control Languagewhich includes commands such as GRANT, and mostly concerned with rights, permissions and other controls of the database system.

GRANT – allow users access privileges to database

REVOKE – withdraw users access privileges given by using the GRANT command

TCL

TCL is short name of Transaction Control Language which deals with transaction within a database.

COMMIT – commits a Transaction

ROLLBACK – rollback a transaction in case of any error occurs

SAVEPOINT – to rollback the transaction making points within groups

SET TRANSACTION – specify characteristics for the transaction