Mysql 批量更新update的表与表之间操作
一、方法一
使用User2表数据更新User表:
update User as a ,User2 as b
set a.role_id=b.set_value
where a.role_id=b.set_key;
二、方法二
使用User2表数据更新User表:
update User
set_key=(SELECT name
FROM User2 where id = User.set_value); set @i:=1;
update Group
SET name=CONCAT(name,'_', (@i:=@i+1))
where name in
(
SELECT a.GroupName
from
(
SELECT name as GroupName
FROM Group
) as a
);