delete 批量删除 及 update 批量更新

连接多表，批量 delete

一般语法： delete from 表A where ...

批量删除语法 ： delete 表A from 表A inner join 表B on ... where ...

delete tbUser    ---易错点
from tbUser
inner join tbGroup_Member on tbUser.user_id =tbGroup_Member.user_id
where tbGroup_Member.user_id='1001'

 

连接多表，批量 update

一般语法 ： update 表A set A1=0,A2=1 where ...

批量更新语法 ： update 表A set A1=B1,A2=B2 from 表A inner join 表B on ... where ...