DDL DML DCL TCL
DDL :
DDL is abbreviation of data Definition Language. it’s used to create and modify the structure of database objects in database.
SELECT – retrieve data from the a database
INSERT – insert data into a table
UPDATE – updates existing data within a table
DELETE – deletes all records from a table, the space for the records remain
MERGE – UPSERT operation (insert or update)
CALL – call a PL/SQL or Java subprogram
EXPLAIN PLAN – explain access path to data
LOCK TABLE – control concurrency
DML :
DML is abbreviation of data Manipulation Language. it’s used to retrieve, store, modify, delete, insert and update information in database.
CREATE – to create objects in the database
ALTER – alters the structure of the 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
DCL :
DCL is abbreviation of data control Language. it’s used to create roles, permissions, and referential integrity similarly it’s used to control access to database by securing it.
GRANT – gives user’s access privileges to database
REVOKE – withdraw access privileges given with the GRANT command
TCL:
TCL is abbreviation of Transactional control Language. it’s used to manage completely different transactions occurring inside a database.
COMMIT – save work done
SAVEPOINT – identify a point in a transaction to which you can later roll back
ROLLBACK – restore database to original since the last COMMIT
SET TRANSACTION – Change transaction options like isolation level and what rollback segment to use
