SQL Statements

1 DML(Data Manipulation Language) [数据操纵]

SELECT - retrives data from the database 
	[从数据库中检索数据]
INSERT - enters new rows 
	[插入新行]
UPDATE - changes existing rows 
	[更新现有行]
DELETE - removed unwanted rows from tables in database
	 [从数据库的表中删除不要的行]
merge

2 DDL(Data Definition Language) [数据定义]

CREATE - set up data structures from tables
ALTER - changes data structures from tables
DROP - removes data structures from tables
rename - 修改表的列名
TRUNCATE
comment

3 DCL(Data Control Language) [数据控制]

GRANT - provides access rights to both the Oracle Database and the structures within it 
    [提供对Oracle数据库及其内部结构的访问权限]
REVOKE - removes  provides access rights to both the Oracle Database and the structures within it
    [移除对Oracle数据库及其内部结构的访问权限]

4 TCL(Transaction Control Lanaguage) [事务控制]

COMMIT
ROLLBACK
SAVEPOINT

5 补充

5.1 DROP | TRUNCATE | DELETE