销售订单子表的含税价要高于采购订子表中同一料号同一个月内含税平均价的7%,增加的销售订单才能保存

create trigger [dbo].[SO_SODetailspricecomparison] on [dbo].[SO_SODetails]
FOR insert as

IF (
(SELECT avg(isnull(so.itaxunitprice,0))
FROM SO_SODetails so,inserted i
WHERE so.cInvCode=i.cInvCode)
<
(SELECT avg(isnull(po.iNatUnitPrice,0)*1.17*1.06)
FROM PO_Podetails po ,inserted i
WHERE po.cinvcode=i.cinvcode AND datediff(month,dArriveDate,getdate())=0 )
)
raiserror('销售价格太低',16,1)