asp.net mvc c＃sqkbulkcopy没有为一个或多个必需参数给出值

No Value given for one or more required parameter

  string excelConnectionString = @\"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=\" + postdir + newFileNameOnServer + \"; Extended Properties=Excel 8.0\";


         using (OleDbConnection connection =new OleDbConnection(excelConnectionString))
         {
             OleDbCommand command = new OleDbCommand(\"Select Month,Year,CountryofExport,CountryofOrigin,Hs_code,quantity,Unit,CustomValue,Type FROM [qryTradeFlowforWeb$]\", connection);
             connection.Open();

         // Create DbDataReader to Data Worksheet
           using (DbDataReader dr = command.ExecuteReader())   // the error coming here
           {
               string sqlConnectionString = ConfigurationManager.ConnectionStrings[\"KMFConnectionString\"].ToString();
               SqlConnection conn = new SqlConnection(sqlConnectionString);
              using (SqlBulkCopy bulkCopy =  new SqlBulkCopy(sqlConnectionString))
              {
                bulkCopy.DestinationTableName = \"ExcelData\";
                bulkCopy.WriteToServer(dr);
              }
           }
      }