Types of DBMS languages

  1) Data Definition Language-DDL

  2) Data Manipulation language - DML

  3) Data Control Language (DCL)

  4) Transaction Control (TCL)

1) Data Definition Language: used to define the database structure or schema. 

Examples:   
                            CRETATE -  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


2) Data Manipulation Language : statements are used for managing data within schema objects. 
Examples :

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

3) Data Control Language : 
 Examples :
                       GRANT - gives user's access privileges to database
                       REVOKE - withdraw access privileges given with the GRANT command

4) Transaction Control Language : statements are used to manage the changes made by DML statements. It allows statements to be grouped together into logical transactions. 

Examples :  

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