如何在Update语句中使用Order by

Question

    AccountHmy|UserHmy|Closing|Reason|              |TimeStamp
    606       |299    |0      |Re-opened for Testing |2015-08-11 10:22:36
    606       |108    |1      |Testing Completed     |2015-08-10 10:22:36
    606       |108    |1      |Re-opened for Testing |2015-08-10 10:15:36

我有一个 SQL 查询结果是 4 行，

      select * from  Synergy.dbo.cu_Close_Account_Log SCAL 
      where SCAL.AccountHmy='602634' order by SCAL.Timestamp desc

现在我需要通过加入之前的 table 来更新另一个 table，我应该只考虑早期结果集中返回的第一个值。

    UPDATE 
            ST 
        SET 
            StatusHmy = (
                            CASE
                                WHEN ST.StatusHmy = 4 AND SCAL.Closing = 0 THEN 5
                                WHEN ST.StatusHmy = 4 AND SCAL.Closing = 1 THEN 2
                            END                          
                        )
        FROM    
            Synergy.dbo.cu_Transition ST
            LEFT JOIN Synergy.dbo.cu_Close_Account_Log SCAL ON SCAL.AccountHmy = ST.AccountHmy
        WHERE
            ST.StatusHmy = 4 AND SCAL.Closing IN ( 0,1 )
        ORDER BY 
            SCAL.Timestamp desc

但是这里的 Order By 抛出了一个错误。如何解决？

Answer 1

如果你只想对一个值使用子查询，那么使用TOP和ORDER BY。这可以在子查询中进行：

UPDATE ST 
    SET StatusHmy = (CASE WHEN ST.StatusHmy = 4 AND SCAL.Closing = 0 THEN 5
                          WHEN ST.StatusHmy = 4 AND SCAL.Closing = 1 THEN 2
                     END )
    FROM Synergy.dbo.cu_Transition ST JOIN
         (select top 1 scal.*
          from  Synergy.dbo.cu_Close_Account_Log SCAL 
          where SCAL.AccountHmy = '602634' 
          order by SCAL.Timestamp desc
         ) scal
         ON SCAL.AccountHmy = ST.AccountHmy
     WHERE ST.StatusHmy = 4 AND SCAL.Closing IN ( 0,1 );

如何在Update语句中使用Order by

How to use Order by in Update statement

mysql

sql

database

sql-order-by

sql-update