Whats is SQL? What is DDL, DML, DCL and TCL?

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Structured Query Language(SQL) as we all know is the database language by the use of which we can perform certain operations on the existing database and also we can use this language to create a database.

DDL

DDL is abbreviation of Data Definition Language. It is used to create and modify the structure of database objects in database.

CREATE – Creates objects in the database
ALTER – Alters objects of the database
DROP – Deletes objects of the database
TRUNCATE – Deletes all records from a table and resets table identity to initial value.

DML

DML is abbreviation of Data Manipulation Language. It is used to retrieve, store, modify, delete, insert and update data in database.

SELECT – Retrieves data from a table
INSERT –  Inserts data into a table
UPDATE – Updates existing data into a table
DELETE – Deletes all records from a table

DCL

DCL is abbreviation of Data Control Language. It is used to create roles, permissions, and referential integrity as well it is used to control access to database by securing it.

GRANT – Gives user’s access privileges to database
REVOKE – Withdraws user’s access privileges to database given with the GRANT command

TCL

TCL is abbreviation of Transactional Control Language. It is used to manage different transactions occurring within a database.

COMMIT – Saves work done in transactions
ROLLBACK – Restores database to original state since the last COMMIT command in transactions
SAVE TRANSACTION – Sets a savepoint within a transaction

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