============SQL分类 数据定义语言(DDL):CREATE ALERT DROP TRUNCATE 数据操纵语言(DML):INSERT UPDATE DELETE SELECT 事务控制语言(TCL):COMMIT SAVEPOINT ROLLBACK 数据控制语言(DCL):GRANT REVOKE DML 创建序列 CREATE SEQUENCE sq_name [start with n][increment by n][maxvalue n][nomaxvalue][cy…