DAL层中删除问题

public static void DeleteOneYearsold(OneYearsold oneYearsold)
        {
            DeleteOneYearsoldById(oneYearsold.Id);
        }        public static int DeleteOneYearsoldById(int id)
        {
            string sql = "DELETE OneYearsold WHERE Id = @Id";            try
            {
                SqlParameter[] para = new SqlParameter[]
                {
                    new SqlParameter("@id", id)
                };                return DBHelper.ExecuteNonQuery(sql, para);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                throw e;
            }
        }
这两个看起来有联系，我初学者，问一下他俩有什么联系啊，下面这个我清楚是通过id来实现删除，上面的又是什么，望大虾们指点。