/// <summary>
 /// 求总记录数
 /// </summary>
 /// <param name="_fname"></param>
 /// <returns></returns>
 private string GetCountData(string _fname)
 {
     if (this.FieldsDictionary.ContainsKey(_fname))
     {
         RealColumnDefine _col = this.FieldsDictionary[_fname];
         DataTable        _dt  = this.QueryResultData.Tables[_col.TableName];
         return(_dt.Compute(string.Format("count({0})", _col.ColumnName), "").ToString());
     }
     else
     {
         return("");
     }
 }
 /// <summary>
 /// 求总和
 /// </summary>
 /// <param name="_fname"></param>
 /// <returns></returns>
 private string GetSumData(string _fname)
 {
     if (this.FieldsDictionary.ContainsKey(_fname))
     {
         RealColumnDefine _col = this.FieldsDictionary[_fname];
         DataTable        _dt  = this.QueryResultData.Tables[_col.TableName];
         if (_dt.Columns[_col.ColumnName].DataType == typeof(decimal))
         {
             return(_dt.Compute(string.Format("sum({0})", _col.ColumnName), "").ToString());
         }
         return("");
     }
     else
     {
         return("");
     }
 }