MySQL-根据子查询更新值 [英] MySQL - Update values based on subquery

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

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