轻松掌握设计Sql Server触发器的原理 （6）

use northwind
go 
create trigger cust_orders_ins3
on order_test
after insert
as 
update cust_test set cstorage=cstorage-inserted.orders
from cust_test,inserted
where cust_test.customerid=inserted.customerid

use northwind
go
create trigger orderdateupdate
on order_test
after update
as
if update (odate)
begin
raiserror('Error',10,1)
rollback transaction
end

use northwind
go
create trigger order_insert5
on order_test
after insert
as
begin
if(select count(*)
from cust_test,inserted
where cust_test.customerid=inserted.customerid)=0
begin
print 'No entry in goods for your order'
rollback transaction
end
if(select cust_test.cstorage from cust_test,inserted 
where cust_test.customerid=inserted.customerid)<
(select inserted.orders from cust_test,inserted 
where cust_test.customerid=inserted.customerid)
begin
print 'No enough entry in goods for your order'
rollback transaction
end
end