將數據從Excel移動到SQL Server時的NullReferenceException

Question

我正在開發一個Web應用程序，在該應用程序中，我必須使用C＃和ASP.NET MVC從給定的Excel文件導入SQL Server中的數據。爲此我遵循this文章。所以我用ExcelDataReader來讀取Excel文件。此外，我在我的代碼中使用SqlBulkCopy將數據插入到數據庫中。下面是我的代碼：

的Create方法

var bData = getBillData(); 

var connString = ConfigurationManager.ConnectionStrings["WASABill"].ConnectionString; 
DataTable table = new DataTable(); 

using (var reader = ObjectReader.Create(bData)) 
{ 
    table.Load(reader); 
} 

using (SqlBulkCopy bcp = new SqlBulkCopy(connString)) 
{ 
       bcp.ColumnMappings.Add("AccountNo", "AccountNo"); 
       bcp.ColumnMappings.Add("BillNo", "BillNo"); 
       bcp.ColumnMappings.Add("Category", "Category"); 
       bcp.ColumnMappings.Add("Billing_Period", "Billing_Period"); 
       bcp.ColumnMappings.Add("Name", "Name"); 
       bcp.ColumnMappings.Add("Address", "Address"); 
       bcp.ColumnMappings.Add("Issue_Date", "Issue_Date"); 
       bcp.ColumnMappings.Add("Due_Date", "Due_Date"); 
       bcp.ColumnMappings.Add("Water_Bill", "Water_Bill"); 
       bcp.ColumnMappings.Add("Sewerage_Bill", "Sewerage_Bill"); 
       bcp.ColumnMappings.Add("Aquifer_Charges", "Aquifer_Charges"); 
       bcp.ColumnMappings.Add("Current_Amount", "Current_Amount"); 
       bcp.ColumnMappings.Add("Arrears", "Arrears"); 
       bcp.ColumnMappings.Add("Service_Charges", "Service_Charges"); 
       bcp.ColumnMappings.Add("Payable_within_DueDate", "Payable_within_DueDate"); 
       bcp.ColumnMappings.Add("Surcharge", "Surcharge"); 
       bcp.ColumnMappings.Add("Payable_after_DueDate", "Payable_after_DueDate"); 
       bcp.ColumnMappings.Add("Payment_History_1", "Payment_History_1"); 
       bcp.ColumnMappings.Add("Paid_1", "Paid_1"); 
       bcp.ColumnMappings.Add("Payment_History_2", "Payment_History_2"); 
       bcp.ColumnMappings.Add("Paid_2", "Paid_2"); 
       bcp.ColumnMappings.Add("Payment_History_3", "Payment_History_3"); 
       bcp.ColumnMappings.Add("Paid_3", "Paid_3"); 
       bcp.ColumnMappings.Add("Area", "Area"); 
       bcp.ColumnMappings.Add("Water_Rate", "Water_Rate"); 
       bcp.ColumnMappings.Add("Sewerage_Rate", "Sewerage_Rate"); 
       bcp.ColumnMappings.Add("Discharge_Basis", "Discharge_Basis"); 
       bcp.ColumnMappings.Add("Pump_Size", "Pump_Size"); 
       bcp.ColumnMappings.Add("Ferrule_Size", "Ferrule_Size"); 
       bcp.ColumnMappings.Add("Meter_Type", "Meter_Type"); 
       bcp.ColumnMappings.Add("Meter_Status", "Meter_Status"); 
       bcp.ColumnMappings.Add("Last_Readin", "Last_Readin"); 
       bcp.ColumnMappings.Add("Current_Reading", "Current_Reading"); 
       bcp.ColumnMappings.Add("Water_Aquiffer_Charges", "Water_Aquiffer_Charges"); 
       bcp.DestinationTableName = "WASA_Bill_Detail"; 
       bcp.WriteToServer(table);     
} 

var rowCount = table.Rows.Count; //Number of rows in data table 
//if (ModelState.IsValid) 
//{ 
// db.WASA_Bill_Detail.Add(wASA_Bill_Detail); 
// db.SaveChanges(); 
// return RedirectToAction("Index"); 
//} 
TempData["RowCount"] = rowCount; 
return RedirectToAction("Index"); 

讀取Excel文件並返回數據作爲一個列表

public IEnumerable<WASA_Bill_Detail> getBillData() 
{ 
     List<WASA_Bill_Detail> billDetaileList = new List<WASA_Bill_Detail>(); 
     //string path = @TempData["FilePath"].ToString();//@"E:\W317.xlsx"; 
     string path = TempData["FilePath"].ToString(); 
     string excelpath = Server.MapPath(path); 
     if(path!=null) 
     { 
      var excelData = new ExcelData(excelpath); 
      var billRecords = excelData.getData("Sheet1"); 
      foreach (var row in billRecords) 
      { 
       var billDetail = new WASA_Bill_Detail() 
       { 
        AccountNo = row["ACCOUNT#"].ToString(), 
        BillNo = row["BILLNO"].ToString(), 
        Category = row["CATEGORY"].ToString(), 
        Billing_Period = row["BILLING_PERIOD"].ToString(), 
        Name = row["NAME"].ToString(), 
        Address = row["ADDRESS"].ToString(), 
        Issue_Date = row["ISSUE_DATE"].ToString(), 
        Due_Date = row["DUE_DATE"].ToString(), 
        Water_Bill = row["WATER_BILL"].ToString(), 
        Sewerage_Bill = row["SEWERAGE BILL"].ToString(), 
        Aquifer_Charges = row["AQUIFER"].ToString(), 
        Current_Amount = row["CURRENT AMOUNT"].ToString(), 
        Arrears = row["ARREARS"].ToString(), 
        Service_Charges = row["SERVICE CHARGES"].ToString(), 
        Payable_within_DueDate = row["PAYABLE WITHIN DUEDATE"].ToString(), 
        Surcharge = row["SURCHARGE"].ToString(), 
        Payable_after_DueDate = row["AFTER DUE DATE"].ToString(), 
        Payment_History_1 = row["PAY HISTORY 1"].ToString(), 
        Paid_1 = row["PAID 1"].ToString(), 
        Payment_History_2 = row["PAY HISOTRY 2"].ToString(), 
        Paid_2 = row["PAID 2"].ToString(), 
        Payment_History_3 = row["PAY HISOTRY 3"].ToString(), 
        Paid_3 = row["PAID 3"].ToString(), 
        Area = row["AREA"].ToString(), 
        Water_Rate = row["WATER RATE"].ToString(), 
        Sewerage_Rate = row["SEWER RATE"].ToString(), 
        Discharge_Basis = row["DISCHAGE"].ToString(), 
        Pump_Size = row["PUMP SIZE"].ToString(), 
        Ferrule_Size = row["FERRULE SIZE"].ToString(), 
        Meter_Type = row["METER TYPE"].ToString(), 
        Meter_Status = row["METER STATUS"].ToString(), 
        Last_Readin = row["LAST READING"].ToString(), 
        Current_Reading = row["CURRENT READING"].ToString(), 
        Water_Aquiffer_Charges = row["AQUIFER CHARGES"].ToString(), 
       }; 
       billDetaileList.Add(billDetail); 
      } 
     }    
     return billDetaileList; 
} 

一切正常我的開發機上的方法。文件正確上傳，然後使用bcp插入到數據庫中。

但我發佈此宿主服務器時NullReferenceException發生在

WASAWeb.Controllers.AdminControllers.WASA_Bill_DetailController.getBillData() +128 

，因爲它是在我的機器的工作100％的罰款我無法理解。我已檢查該文件是否已正確上傳到服務器。

對此有何幫助？

Answer 1

您可以使用此：

private string GetStringValue(object obj) 
{ 
    string str = null; 
    if(obj != null) 
     str = obj.ToString().Trim(); 
    return str; 
} 

呼叫

...... 
AccountNo = GetStringValue(row["ACCOUNT#"]) 
......