public List <School三级类别表> 查询三级类别s(int id)
        {
            try
            {
                StringBuilder sb   = new StringBuilder();
                string        sql  = string.Format("SELECT * FROM 三级类别表 WHERE SSID =  {0} ", id);
                SqlDataReader read = DBHelper.ExecuteReader(DBHelper.ConnectionString, CommandType.Text, sql.ToString());

                List <School三级类别表> list = new List <School三级类别表>();
                //School三级类别表 modelx = new School三级类别表();
                //modelx.ID = 0;
                //modelx.名称 = "全部";
                //list.Add(modelx);
                while (read.Read())
                {
                    School三级类别表 model = new School三级类别表();
                    model.ID = Convert.ToInt32(read["ID"]);
                    model.称  = read["名称"].ToString();
                    list.Add(model);
                }
                return(list);
            }
            catch (Exception)
            {
                throw;
            }
        }
        public List <School三级类别表> 级(string kind)
        {
            try
            {
                StringBuilder sb   = new StringBuilder();
                string        sql  = string.Format(" SELECT * FROM 三级类别表 WHERE SSID =  (SELECT ID FROM 二级类别表 WHERE 名称 = '{0}')  ", kind);
                SqlDataReader read = DBHelper.ExecuteReader(DBHelper.ConnectionString, CommandType.Text, sql.ToString());

                List <School三级类别表> list = new List <School三级类别表>();
                while (read.Read())
                {
                    School三级类别表 model = new School三级类别表();
                    model.ID = Convert.ToInt32(read["ID"]);
                    model.称  = read["名称"].ToString();
                    list.Add(model);
                }
                return(list);
            }
            catch (Exception)
            {
                throw;
            }
        }