Question

以下循环根据同一个表中是否存在其他记录有条件地设置@EndDate。基本上，如果给定的ReferenceTypeId和每个PersonId，KeepId和RemoveId至少存在一条记录，我们只想将当前日期分配给@EndDate。

如何在没有循环的情况下编写此Update语句。

    DECLARE ReferenceType_Cursor CURSOR FOR  
    SELECT ID FROM CORE.PersonExternalReferenceType 
    OPEN ReferenceType_Cursor   
    FETCH NEXT FROM ReferenceType_Cursor INTO @RefTypeId   

    WHILE @@FETCH_STATUS = 0 
    BEGIN
        SET @ENDDATE = NULL

        IF( EXISTS (SELECT 1 FROM CORE.PersonExternalReferences WHERE ReferenceTypeId = @RefTypeId AND PersonId = @KeepId) AND 
            EXISTS (SELECT 1 FROM CORE.PersonExternalReferences WHERE ReferenceTypeId = @RefTypeId AND PersonId = @RemoveId))
        BEGIN
            SET @ENDDATE     = @CURRENTDATE
        END

        UPDATE CORE.PersonExternalReferences  
        SET  
            PersonId        = @KeepID,
            ModifiedBy      = @USERNAME,
            ModifiedDate    = @CURRENTDATE,
            StartDate       = COALESCE(StartDate,CreatedDate,@STARTDATE),
            EndDate         =  @ENDDATE
        WHERE ReferenceTypeId = @RefTypeId AND PersonId = @RemoveID

    FETCH NEXT FROM ReferenceType_Cursor INTO @RefTypeId
    END
    CLOSE ReferenceType_Cursor   
    DEALLOCATE ReferenceType_Cursor

Answer 1

只是为了澄清你的要求：

您想要更新PersonId = @RemoveID的每个PersonExternalReferences。

对于每个记录，检查是否存在另一个具有相同ReferenceTypeId 和PersonId = @KeepId的PersonExternalReferences 。如果存在，则设置EndDate = @ENDDATE，否则设置EndDate = null。

为了确保它是正常工作的代码，我创建了一个简化的准备运行示例。

架构设置为：

create table PersonExternalReferenceType ( id varchar(100) ) go create table PersonExternalReferences ( PersonId int, ReferenceTypeId varchar(100), ModifiedDate datetime, EndDate datetime ) go insert PersonExternalReferenceType values ('foo'),('bar') ; insert PersonExternalReferences values (1,'foo',null,null), (2,'foo',null,null), (3,'foo',null,null), (4,'bar',null,null) ;

实际的更新声明是

declare @KeepId int = 1; declare @RemoveId int = 2; update PersonExternalReferences set ModifiedDate = getdate(), EndDate = case when exists ( select 1 from PersonExternalReferences as other where other.PersonId = @KeepId and other.ReferenceTypeId = PersonExternalReferences.ReferenceTypeId ) then getdate() else null end where PersonId = @RemoveId;

然后再次使用
运行
declare @KeepId int = 3; declare @RemoveId int = 4;

最终结果是

+----------+-----------------+-------------------------+-------------------------+ | PersonId | ReferenceTypeId | ModifiedDate | EndDate | +----------+-----------------+-------------------------+-------------------------+ | 1 | foo | NULL | NULL | | 2 | foo | 2016-03-03 10:27:40.507 | 2016-03-03 10:27:40.507 | | 3 | foo | NULL | NULL | | 4 | bar | 2016-03-03 10:27:40.517 | NULL | +----------+-----------------+-------------------------+-------------------------+

Answer 2

@CURRENTDATE

＆＃13;

 UPDATE CORE.PersonExternalReferences  
        SET  
            PersonId        = @KeepID,
            ModifiedBy      = @USERNAME,
            ModifiedDate    = @CURRENTDATE,
            StartDate       = COALESCE(StartDate,CreatedDate,@STARTDATE),
            EndDate         =  
case when (ReferenceTypeId = @RefTypeId 
AND PersonId = @KeepId  
and PersonID = @RemoveId) then 
 @CURRENTDATE 
else null end 
    /*Then you don't need to filter at all if you wanna loop trought whole table...   WHERE ReferenceTypeId = @RefTypeId AND PersonId = @RemoveID
*/

＆＃13;

Answer 3

我有两个解决方案。您只需根据需要编辑分区列和列：

update a
set a.enddate = @enddate
from abc as a
where ReferenceTypeId = @RefTypeId AND PersonId = @RemoveID and
exists(select 1 from abc as b where b.ReferenceTypeId  = a.ReferenceTypeId  group by ReferenceTypeId,PersonId,KeepId,RemoveId  having count(*) >1)

另一个：

update a
set a.enddate = @enddate
from
(
select *, count(*) over (partition by ReferenceTypeId,PersonId,KeepId,RemoveId) as rn
from abc
) as a
where a.rn > 1 and ReferenceTypeId = @RefTypeId AND PersonId = @RemoveID

如果这有帮助，请告诉我。

条件设置在没有游标的Update语句中

3 个答案: