Question

我有一个像这样的桌子：

----------------------------------------------------------
|                Actions                                 |
----------------------------------------------------------
| action_id | user_id | action_active | action_cancelled |
----------------------------------------------------------
|     1     |    1    |       0       |         0        |
----------------------------------------------------------
|     2     |    2    |       1       |         0        |
----------------------------------------------------------
|     3     |    1    |       0       |         0        |
----------------------------------------------------------
|     4     |    2    |       0       |         0        | 
----------------------------------------------------------

如果用户将他的每一行都设置为action_active = 0，我想将user_id的所有action_cancelled都更新为1。如果他至少有一个action_active为1，请不要更新。

在此示例中，应该将第1行和第3行的action_cancelled更新为1，因为用户1的每个action_active都为0。

我考虑过类似的事情，但是我不确定它是否正确：

UPDATE actions 
SET a.active_cancelled = 1 
WHERE (SELECT p.user_id, SUM(p.action_active) as sum_p FROM actions p GROUP BY user_id WHERE a.user_id = p.user_id AND sum_p = 0);

我被困在那里。我怎么说：“如果用户的所有行都为action_active = 0，请更新它们”

希望获得帮助！

Answer 1

您可以使用HAVING和JOIN来完成

    UPDATE actions a
    JOIN 
   (
    SELECT p.user_id, SUM(p.action_active) as sum_p 
     FROM actions p 
     GROUP BY user_id
     HAVING sum_p = 0)
   b ON a.user_id=b.user_id
    SET a.action_cancelled = 1

Answer 2

您可以使用not exists：

update t
     set t.active_cancelled = 1 
where not exists (select 1 from t t1 where t1.user_id = t.user_id and t1.action_active = 1);

Answer 3

一种可能的解决方案是，

update actions
inner join(
    select user_id,sum(if(action_active=1,1,0))as inactive from actions group by 
    user_id having inactive=0
)as B on B.user_id=temp.user_id
set actions.action_cancelled=1;

如果每列等于相同的值，则MySQL更新行

3 个答案: