Question

小白求SQL 触发器：现有A，B两表，要求B表新增或更改时，A表中的PRICE 字段更新到B中的PRICE ，为空不更新

A:
ID NAME PRICE
1 book 15.00
2 cup 10.00
------------------------------
B:
ID NAME PRICE geshu
1 book 15.00 10
2 cup 10.00 20
MB:
MB001 MB002 MB003
1 book 15.00
2 cup 10.00
-----
TB:
TB004 TB005 TB007 geshu
1 book 15.00 10
2 cup 10.00 20

MB表是先有的，那么我在插入或者更改TB表时，我想把MB表的MB003更新到TB表的TB007 （MB001=TB004）

Answer 1

create TRIGGER B_U
ON dbo.B
for insert UPDATE
AS
if exists（select price from inserted where price is not null）
update dbo.B
set PRICE
from inserted,dbo.A
where inserted.ID=dbo.B.ID and inserted.NAME =dbo.A.NAME

Answer 2

create TRIGGER B_U
ON dbo.B
for insert UPDATE
AS
update dbo.B
set PRICE
from inserted,dbo.A
where inserted.ID=dbo.B.ID and inserted.NAME =dbo.A.NAME