Question

我将此表命名为SubscriptionCharity，其内容如下：

SubscriptionId       ChannelURI       CharUserID
1                       AX                12
2                       ZA                7
3                       AX                10

我想检查一个特定的CharUserId，如果表中的任何记录具有相同的通道uri并将其设置为null，那么在此表中“Subcriptionid = 1”应该设置为null

我有两个查询，一个在MS SQL Managment m中工作但不适用于LINQ：（它不会影响行）

UPDATE SubscriptionCharProg 
Set ChannelURI = null 
FROM SubscriptionCharProg as t1
INNER JOIN SubscriptionCharProg as t2 
    on t1.ChannelURI = t2.ChannelURI 
    and t1.DeviceId = t2.DeviceId 
WHERE CharUserId! = 5

和另一个适用于LINQ但不适用于MS SQL Managment：（MS SQL管理错误：无效的对象名称“t1”）

context.ExecuteStoreCommand("UPDATE t1 Set t1.ChannelURI = 1 FROM SubscriptionCharProg as t1 INNER JOIN  
  SubscriptionCharProg as t2 on t1.ChannelURI = t2.ChannelURI WHERE t1.CharUserId! = " 
  + charuserID + "", null);

另外，主要问题是，两个查询都使每个channelURi为空，无论它是否等于

有什么想法吗？

编辑：如果具有特定charuserID的记录存在两次或更多次，则保留并且不将其设置为空

Answer 1

更改第一行：

UPDATE SubscriptionCharProg

到

UPDATE t1

Answer 2

试试这个：

UPDATE t1
SET ChannelURI = null 
FROM SubscriptionCharProg as t1
INNER JOIN SubscriptionCharProg as t2 
    on t1.ChannelURI = t2.ChannelURI 
    and t1.DeviceId = t2.DeviceId 
    and t1.CharUserID <> t2.CharUserID
WHERE t2.CharUserID = 5

Answer 3

update quiz_subgroup as sg  

inner join (select qq_qsg_id, count(qq_id) as cnt_ques from quiz_questions group by qq_qsg_id) as ques on(ques.qq_qsg_id = sg.qsg_id) 

set sg.qsg_count_of_questions = ques.cnt_ques;

使用内部联接更新查询....？

3 个答案: