〇、概述

1、资料

sql连表删除：http://www.lanxinbase.com/?tag=sql%E8%BF%9E%E8%A1%A8%E5%88%A0%E9%99%A4

sql实现两表关联更新：https://blog.csdn.net/qq_43429919/article/details/124036257

2、组成

一、更新操作

（一）传统方式

Update student Set Sage=22
Where Sno=’201215121’;

（二）连表方式

1、pgsql

UPDATE (要更新的表) table1 t1
SET t1.字段1 = t2.字段1, t1.字段2 = t2.字段2,
FROM
    (数据来源表) table2 t2
WHERE
    t1.key = t2.key

2、MySQL

UPDATE  (要更新的表)  table1 t1, table2 t2
SET t1.字段1 = t2.字段1, t1.字段2 = t2.字段2,
WHERE
    t1.key = t2.key

二、删除操作

（一）传统方式

Delete From SC Where Son in(
Selete Sno From Student
Where Sdept=’CS’);

（二）连表方式

delete FROM `t1` using `t1`
left join `t2` on t1.id= t2.id
where 1 and t2.id is null;