SQLdelete

select * from user1;

| id | username | +----+----------+ | 1 | user1 | | 2 | user2 | | 3 | user3 | | 99 | I am 99 |

delete from user1 where id=99;

select * from user1;

| id | username | +----+----------+ | 1 | user1 | | 2 | user2 | | 3 | user3 |

删除表中全部的数据

delete from user1;

delete from user1;

select * from user1;
Empty set (0.00 sec)

使用 delete 的时候最后先用 select 看下

select * from .. 的结果就是 delete from ... 执行的时候被删除的东向

清空一个表是使用 truncate table user1 等价上面的 delete from user1
删除一个表是使用 drop table tablename
删除一个数据库使用 drop database databasename

SQL -- delete