当数值为时,触发器不运算,怎么办?
CREATE TRIGGER ZJC_OUT3 ON dbo.zjc_out
FOR INSERT, UPDATE, DELETE
AS
SET NOCOUNT ON
UPDATE zjc_plan
SET out_num=zjc_plan.out_num-deleted.out_num
FROM zjc_plan,deleted
WHERE zjc_plan.materials_code=deleted.materials_code and zjc_plan.contract=deleted.contract
UPDATE zjc_plan
SET out_num=zjc_plan.out_num+inserted.out_num
FROM zjc_plan,inserted
WHERE zjc_plan.materials_code=inserted.materials_code and zjc_plan.contract=inserted.contract
SET NOCOUNT OFF