Question

我构建了一个触发器，只要将某些数据插入到Sales表中，就会触发该触发器。当它触发时，它会在“帐户”表中更新剩余的购买金额，并按“销售”表中的销售总金额减去该金额。但触发器给出了错误的结果。这是代码：

CREATE TRIGGER [dbo].[TRG_Conta_Insert]
ON [dbo].[Sale]
FOR INSERT, UPDATE
AS
BEGIN

declare @IDAccount bigint
declare @SaleTotalAmount money
declare @RemainingAmount money

select @IDAccount= Inserted.ID_Account, @SaleTotalAmount = Sale.Amount, @RemainingAmount = RemainingAmount from Inserted, Account
if (@IDAccount is not null) and (@RemainingAmount - @SaleTotalAmount >= 0)      
    begin transaction
        update Account set RemainingAmount = @RemainingAmount - @SaleTotalAmount where Account.ID_Account = @IDAccount 
    commit

为什么触发器在RemainingAmount列中更新了Account表并显示错误的结果？

Answer 1

你的整个触发器应该是这样的。

update a set RemainingAmount = a.RemainingAmount - s.SaleTotalAmount 
from inserted i
join Account a on i.SomeKey = a.SomeKey
join Sale s on s.SomeOtherKey = a.SomeOtherKey

另外，请勿将交易置于触发器中。你问的是问题，因为sql server中的嵌套事务是一个神话。我会首先重新考虑你在这里做的事情。您实际上是通过触发器存储计算值。在sql server中有计算列，这似乎比触发器更适合。

插入触发器给出了错误的结果

1 个答案: