:-: MySQL [MySQL 官网](https://www.mysql.com/) [MySQL教程](https://www.runoob.com/mysql/mysql-tutorial.html) ``` //查询表内所有信息20条 SELECT * FROM `school` LIMIT 20; //查询指定分类信息20条ID倒序查询 SELECT * FROM `sos` WHERE s_id=13 order by id desc LIMIT 20; //批量删除指定分类信息 DELETE FROM `sos` WHERE s_id=13; //truncate--删除所有数据，保留表结构，不能撤销还原 truncate table `表名`; //数据库中把ID自增长重置成1： DBCC CHECKIDENT ('表名', RESEED, 0) ``` ## ##