About SQL.

About SQL: - SQL stands for structured query language. SQL are used for communicate with the  database server. SQL has the following types.

Statement	Description
SELECT	Retrieves data from the database
INSERT UPDATE DELETE MERGE	Enters new rows, changes existing rows, and removes unwanted rows from tables in the database, respectively. Collectively known as data manipulation language (DML).After DML need to execute COMMIT to change save in your oracle database.
CREATE ALTER DROP RENAME TRUNCATE	Sets up, changes, and removes data structures from tables. Collectively Known as data definition language (DDL). Auto COMMIT. After execute any DDL statement database change will be auto save.
COMMIT ROLLBACK SAVEPOINT	Manages the changes made by DML statements. Changes to the data can be grouped together into logical transactions.
GRANT REVOKE	Gives or removes access rights to both the Oracle database and the structures within it. Collectively known as data control language (DCL).