mysql update 四种情况

级联更新第1种情况：

update t1, t2

set t1.x = t2.x, t1.y = t2.y

where t1.id = t2.id

级联更新第2种情况：

update t1,

(select * from t2) as t2

set t1.x = t2.x, t1.y = t2.y

where t1.id = t2.id

级联更新第3种情况：

update (select c from t1 group by c) as temp, t2, t1

set t1.x = t2.x, t1.y = t2.y

where t1.id = t2.id and temp.id = t2.id

级联更新第4种情况：

update t1 left join t2 on t1.id = t2.id

set t1.x = t2.x, t1.y = t2.y

where t1.id = xx

本文出自 “晴朗” 博客，请务必保留此出处http://guitarboy.blog.51cto.com/3121650/1365170

mysql update 四种情况,布布扣,bubuko.com

原文：http://guitarboy.blog.51cto.com/3121650/1365170