DDL

Data Definition Language (DDL) statements are used to define the database structure or schema.

o CREATE - to create objects in the database

o ALTER - alters the structure of the database

o DROP - delete objects from the database

o TRUNCATE - remove all records from a table.

o COMMENT - add comments to the data dictionary

o RENAME - rename an object

DML

Data Manipulation Language (DML) statements are used for managing data within schema objects.

o SELECT - retrieve data from the a database

o INSERT - insert data into a table

o UPDATE - updates existing data within a table

o DELETE - deletes all records from a table, the space for the records remain

o MERGE - UPSERT operation (insert or update)

o CALL - call a PL/SQL or Java subprogram

o EXPLAIN PLAN - explain access path to data

o LOCK TABLE - control concurrency

DCL

Data Control Language (DCL) statements. Some examples:

o GRANT - gives user's access rights to database

o REVOKE - withdraw access rights given with the GRANT command