根据子查询更新值

根据子查询更新值

本文介绍了MySQL-根据子查询更新值的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

让我说我选择了,这使我从表1中返回:

let's say I have select, which return me from table1:

ID  Name
 1  Bob
 2  Alice
 3  Joe

然后我想要基于此结果在另一个表中更新值:

Then I want UPDATE values in another table based on this result:

UPDATE table2 SET Name = table1.Name WHERE ID = table1.ID

据我了解,我只能在一个地方进行内部选择,例如:

As I understood, I can only do internal select in one place, like:

UPDATE table2 SET Name = (select Name from table1) WHERE ...

而且我不知道如何指定WHERE条件.

And I don't know how to specify WHERE-condition.

推荐答案

您要做的就是像这样联接表.

all you should do is just join the tables like this.

UPDATE table2 t2
JOIN table1 t1 ON t1.id = t2.id
SET t2.name = t1.name;

加入结果

如果您打算通过选择执行此操作,则可以这样做.

if you are set on doing it with a select you could do it like this.

UPDATE table2 t2,
(   SELECT Name, id
    FROM table1
) t1
SET t2.name = t1.name
WHERE t1.id = t2.id

SELECT的结果

这篇关于MySQL-根据子查询更新值的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

08-19 01:54