public DataTable GetList(string stringWhere)
        {
            DataTable dt  = null;
            string    sql = "select stuId as 学生id,stuName as 学生姓名,stuSex as 性别,stuNation as 学生民族,stuAdress as 家庭住址,stuTel  as 电话号码 from stuinfo";

            if (string.IsNullOrEmpty(stringWhere.Trim()))
            {
                dt = SqlHelper.DataTable(sql);
            }
            return(dt);
        }