在创建带输出参数和返回值的存储过程时---犯下的一个低级错误

if exists(select * from sysobjects where name='usp_AllPmsTest')
    drop proc usp_AllPmsTest
go
create proc usp_AllPmsTest
@cityName nvarchar(30),
@id int output
as
begin
    insert into ShopModelBak values(@cityName,1,1)
    set @id=@@identity
 
    select CPName,CName,SName,MType,MName,Mprice from ShopMenu
    inner join ShopModel on ShopMenu.MShopId=ShopModel.SId
    inner join View_CityData on ShopMenu.MCityId=CId
    where CName=@cityName
 
    return (select count(1) from ShopMenu)
end
go
declare @total int,@id int
exec @total=usp_AllPmsTest '滨湖区',@id output
select @id Id,@total total

var pms = new SqlParameter[]
                          {
                          new SqlParameter("@cityName", "滨湖区"),
                          new SqlParameter("@id", SqlDbType.Int),
                          new SqlParameter("@total", SqlDbType.Int)
                          };
            pms[1].Direction = ParameterDirection.Output;
            pms[2].Direction = ParameterDirection.ReturnValue;
            var list = SQLHelper.ExecuteReader<ShopMenu>("usp_AllPmsTest", CommandType.StoredProcedure, pms);
            foreach (var item in list)
            {
                Console.WriteLine(item.MName + " " + item.MPrice);
            }
            Console.WriteLine("刚才插入的ID是：{0},总共{1}条数据", pms[1].Value, pms[2].Value);