z 怎样解决字段重复插入的问题

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
go



ALTER trigger [t1_goods_to_stock1] on [dbo].[goods]
for insert
as

begin
declare @T_count int
declare @T_id  nchar(10)
select @T_id=G_id,@T_count=G_count from inserted
 
   if   (not exists(select G_id from goods where G_id=@T_id))begin
   
insert into stock( T_id,T_count) select G_id,G_count from goods
end
end