Four types of SQL classification DDL,DML,DCL,TCL

- Data Definition language objects used to define a database, such as tables, views, indexes, etc.
DDL does not require a commit.
CREATE
Alter
DROP
TRUNCATE
COMMENT
RENAME


DML  - Data Manipulation Language Update, add and delete records in database tables such as UPDATE, INSERT, delete
Provided by the DBMS for use by a user or programmer to implement operations on data in a database.
DML is divided into two classes: interactive DML and embedded DML.
Depending on the level of the language, DML can be divided into procedural DML and non-procedural DML two species.
A commit is required.
SELECT
INSERT
UPDATE
DELETE
MERGE
Pager
EXPLAIN PLAN
LOCK TABLE

DCL (Data control problem) Data Control Language –data control language refers to setting user permissions and controlling transaction statements such as Grant,revoke,if... else,while, BEGIN TRANSACTION
Grant Authorization
REVOKE Cancel Authorization


DQL (data query problem) (¡ï ★) data Query Language –data query Languageselect

Four types of SQL classification DDL,DML,DCL,TCL