Question

我正在尝试更新表格中的列。目标是获取当前值并从不同的表中减去该值。以下是我正在看的内容：

update LS   
    set LS.Quantity = (LS.Quantity - 
    ( 
        select top 1 LSM.Quantity 
        from tblLocationStockMovement LSM
            join tblLocation L on L.ID=LSM.LocationID
            join tblStock S on S.ID=LSM.StockID
            join tblLocationStock LS on LS.StockID=LSM.StockID
        where 
            LSM.StockID=LS.StockID 
            and MoveTypeID=16
            and dateadd(DAY, DATEDIFF(day,0,DateCreated),0)='2016-08-30 00:00:00.00')
    )

from tblLocationStock LS    
    join tblLocation L on L.ID=LS.LocationID
    join tblStock S on S.ID=LS.StockID
    join tblLocationStockMovement LSM on LS.StockID=LSM.StockID

tblLocationStockMovement表具有我需要从tblLocationStock表中减去的值。它们都可以使用tblStock加入StockID。我希望它会减去两个表中引用的相同股票的价值。现在它只是为每个项目做相同的数字。

我最后可能不需要join，我只是使用它来添加where来测试特定项目，然后再为每个项目执行此操作。你知道我哪里出错吗？

编辑：感谢大卫修复我的格式。我没有太多使用这个网站，所以我不熟悉发布内容的正确方法。

Edit2：

你们三个人都有类似的想法，奇怪的是，有时有效。

以下是我现在正在运行的内容：

update LS
     set LS.Quantity=(ISNULL(LS.Quantity,0)-ISNULL(LSM.Quantity,0))
         from tblLocationStock LS
             join tblLocation L on L.ID=LS.LocationID
             join tblStock S on S.ID=LS.StockID
             join tblLocationStockMovement LSM on LSM.StockID=S.ID
         where L.LongDescription='Cafe'
             and MoveTypeID=2
             and PLU = 715

问题是结果发生了变化，我不知道为什么。

select LSM.Quantity
from tblLocationStockMovement LSM
     join tblLocation L on L.ID=LSM.LocationID
     join tblStock S on S.ID=LSM.StockID
where L.LongDescription='Cafe'
    and PLU=715
    and MoveTypeID=2

始终导致120。

 select LS.Quantity
    from tblLocationStock LS
        join tblLocation L on L.ID=LS.LocationID
        join tblStock S on S.ID=LS.StockID
    where L.LongDescription='Cafe'
        and PLU = 715

总是得到53.因此，您可能希望update语句的结果始终为-67。有时会这样，但有时我会得到5分，-43分或29分。这是否有理由说答案会有所不同？

Answer 1

你也可以试试这个：

UPDATE LS   
    SET LS.Quantity = (LS.Quantity-LSM.Quantity)
FROM tblLocationStockMovement LSM
JOIN tblLocation L ON L.ID=LSM.LocationID
JOIN tblStock S ON S.ID=LSM.StockID
JOIN tblLocationStock LS ON LS.StockID=LSM.StockID
WHERE LSM.StockID=LS.StockID 
    AND MoveTypeID=16
    AND dateadd(DAY, DATEDIFF(DAY,0,DateCreated),0)='2016-08-30 00:00:00.00')

Answer 2

试试这个：

update LS   
    set LS.Quantity = ISNULL(LS.Quantity,0) - ISNULL(LSM.Quantity,0)
from tblLocationStock LS    
join tblLocation L on L.ID=LS.LocationID
join tblStock S on S.ID=LS.StockID
join tblLocationStockMovement LSM on LS.StockID=LSM.StockID
    and MoveTypeID=16
    and dateadd(DAY, DATEDIFF(day,0,DateCreated),0)='2016-08-30 00:00:00.00'

Answer 3

试试这个：

update LS
set LS.Quantity=LS.Quantity-LSM.Quantity
from tblLocationStock LS
    join tblLocation L on L.ID=LS.LocationID
    join tblStock S on S.ID=LS.StockID
    join tblLocationStockMovement LSM on LS.StockID=LSM.StockID
where LSM.movetypeid=16
    and LSM.datecreated = '08/30/2016'

使用另一个表

3 个答案: