Question

我有3张桌子：

transaction(IDtransaction,IDperson,IDPos,IDStore,TotalValue,Date)
items(IDtransaction,IDItem,IDproduct,Quantity)
persons(IDperson, balance)

我要完成的工作是，在总值大于该人的余额时从交易中删除，但是当我同时插入错误和正确的记录时，它似乎不起作用。为什么不起作用？

create trigger trigger4
on transaction
After insert,update
As
BEGIN   

delete transaction
FROM inserted i
where transaction.IDtransaction=i.IDtransaction AND EXISTS (select * from inserted i, persons p
                where i.IDperson=p.IDperson 
                and i.TotalValue > p.balance) 

if @@ROWCOUNT > 0
begin
print('Error!')
    if exists(select 1 from deleted) and exists (select 1 from inserted) --check if it is an update
    begin
    SET IDENTITY_INSERT transaction ON

    insert into transaction(IDtransaction,IDperson,IDPos,IDStore,TotalValue,Date)
    select d.IDtransaction,d.IDperson,d.IDPos,d.IDStore,d.TotalValue,d.Date
    from deleted d
    where d.IDtransaction not in (select t.IDtransaction from transaction t)

    SET IDENTITY_INSERT transaction OFF

    end
end             
END

Answer 1

我不感到惊讶，因为它不会引发语法错误，但这有点不对：

delete transaction
FROM inserted i
where transaction.IDtransaction=i.IDtransaction AND EXISTS (select * from inserted i, persons p
                where i.IDperson=p.IDperson 
                and i.TotalValue > p.balance)

因为您不是joining inserted to transaction，所以DELETE与FROM无关。

SQL触发器-插入后更新错误和正确的值

1 个答案: