触发器,新数据插入前如何删除已存在的相同记录

create trigger tr_T_SteelSample_LG on T_SteelSample_LG instead of insert as begin declare @Analyze_code varchar(100),@Analyze_datetime datetime select @Analyze_code=Analyze_code,@Analyze_datetime=Analyze_datetime from inserted if exists (select * fr