MSSQLServer中的触发器问题(100分)

小弟，正做一供销存系统（Delphi+SQLServer7.0).本人负责存货一块，想通过原材料入
库单的入库，自动生成该原材料在原材料库存中的记录。即原材料库存中无该原材料
通过，新进入一批原材料。该原材料入库单的入库，触发一触发器，生成该原材料在库存
表中的记录。
Table BillMaterialsIntoStoreroom(BillNu,Time,MaterialNu,MaterialNa,MaterialAmount)
MaterialStoreroom(MaterialNu,MaterialNa,MaterialAmount)

CREATE TRIGGER BMTG ON BillMaterialsIntoStoreroom
FOR INSERT, UPDATE, DELETE AS

update MaterialStoreroom
set MaterialAmount = MaterialStoreroom.MaterialAmount + deleted.MaterialAmount
from MaterialStoreroom, deleted
where MaterialStoreroom.MaterialNu = deleted.MaterialNu

update MaterialStoreroom
set MaterialAmount = MaterialStoreroom.MaterialAmount - inserted.MaterialAmount
from MaterialStoreroom, inserted
where MaterialStoreroom.MaterialNu = inserted.MaterialNu

Insert Into MaterialStoreroom(MaterialNu,MaterialNa,MaterialAmount)
select MaterialNu,MaterialNa,MaterialAmount from inserted
where MaterialNu not in (select MaterialNu from MaterialStoreroom)



-- 试试！

接受答案了.