MySQL - 基于子查询更新值
假设我有选择，它从 table1 中返回:
let's say I have select, which return me from table1:
ID Name
1 Bob
2 Alice
3 Joe
然后我想根据这个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
你应该做的就是像这样加入表格.
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;
加入的结果
如果你打算用一个选择来做，你可以这样做.
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
选择结果
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