爲什麼我的代碼在數據表中填充單元時停止？

我想從accessDatabase中寫入特定的單元格數據到數據表中。我使用SELECT查詢來獲取這些數據，但是當將數據寫入數據表中的特定單元格時，循環在迭代之前會中斷一次，即使它應該迭代兩次。爲什麼我的代碼在數據表中填充單元時停止？

下面是我使用的代碼：

DataTable dt = new DataTable(); // Creates Table 
dt.Clear(); 

dt.Columns.Add("Hol/Abs", typeof(string));  // Column 0 
dt.Columns.Add("FirstDay", typeof(DateTime)); // Column 1 
dt.Columns.Add("LastDay", typeof(DateTime)); // Column 2 
dt.Columns.Add("TotalDays", typeof(int));  // Column 3 
dt.Columns.Add("Reason", typeof(string));  // Column 4 

LblName.Text = PassName; //Loads Name 

string ConnString = @"Provider = Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\\HoliPlanData.accdb;Persist Security Info=False"; 

string Query = "SELECT PayrollNo FROM [Employee] WHERE (FirstName + ' ' + LastName) = @Name"; 
string CountQuery = "SELECT COUNT(*) FROM [Holiday]"; 
     string GetStartQuery = "SELECT StartDate FROM [Holiday] WHERE PayrollNo = @PayrollNo"; 
     string GetEndQuery = "SELECT EndDate FROM [Holiday] WHERE PayrollNo = @PayrollNo"; 
     string GetReasonQuery = "SELECT Reason FROM [Holiday] WHERE PayrollNo = @PayrollNo"; 
     using (OleDbConnection conn = new OleDbConnection(ConnString)) 
     using (OleDbCommand GetPayroll = new OleDbCommand(Query, conn))    
     { 
      conn.Open();     
      GetPayroll.Parameters.Add("@Name", OleDbType.VarChar).Value = LblName.Text; 
      int GotPayroll = Convert.ToInt32(GetPayroll.ExecuteScalar()); //Uses Query to Get PayrollNo 
      OleDbCommand CountRowsInHol = new OleDbCommand(CountQuery, conn); 
      CountRowsInHol.Parameters.AddWithValue("@PayrollNo", OleDbType.Integer).Value = GotPayroll; 
      int HolidayCount = (int) (CountRowsInHol.ExecuteScalar()); //Uses CountQuery to Get HowMany lines are in [Holiday] 
      int LoopCount = 0; 
      while (LoopCount <= HolidayCount) //Will go though all Lines in [Holiday] 
      {      
       OleDbCommand GetStart = new OleDbCommand(GetStartQuery, conn); 
       OleDbCommand GetEnd = new OleDbCommand(GetEndQuery, conn); 
       OleDbCommand GetReason = new OleDbCommand(GetReasonQuery, conn); 
       GetStart.Parameters.Add("@PayrollNo", OleDbType.Integer).Value = GotPayroll; 

       GetEnd.Parameters.Add("@PayrollNo", OleDbType.Integer).Value = GotPayroll; 
       GetReason.Parameters.Add("@PayrollNo", OleDbType.Integer).Value = GotPayroll; 
       DateTime StartHold = Convert.ToDateTime(GetStart.ExecuteScalar()); 
       DateTime EndHold = Convert.ToDateTime(GetEnd.ExecuteScalar()); 
       string ReasonHold = (GetReason.ExecuteScalar()).ToString(); 
       dt.Rows[LoopCount]["FirstDay"] = StartHold; 
       dt.Rows[LoopCount]["LastDay"] = EndHold; 
       dt.Rows[LoopCount]["Reason"] = ReasonHold; 
       LoopCount = LoopCount + 1; 
      } 
     }

我知道它的長，但它是非常基本的。代碼中斷..

dt.Rows [LoopCount] [「FirstDay」] = StartHold;

..不寫入數據表。任何幫助或建議將不勝感激，也很開放，以更好地更好地格式化我的代碼的建議，所以它更容易閱讀和更普遍的標準。

來源

2016-03-04 Josh

我沒有看到你曾經填充數據錶行。一個好的做法是將代碼封裝在Try/Catch中，並閱讀異常消息。 – Crowcoder

感謝您的幫助，CrowCoder把我放在了正確的方向。我從不添加行！使用這段代碼一切都很精彩，所以希望其他noobie編碼者不會被卡住只要我！

從dt.rows [LoopCount]替換爲以下

DataRow NewLine = dt.NewRow(); 
NewLine["Hol/Abs"] = "Holiday"; 
NewLine["FirstDay"] = StartHold; 
NewLine["LastDay"] = EndHold; 
NewLine["TotalDays"] = (EndHold - StartHold); 
NewLine["Reason"] = ReasonHold; 
dt.Rows.Add(NewLine);

來源

2016-03-04 13:00:24 Josh

-1

不能完全確定，但可能它是一個小錯誤，因爲更換：

dt.Rows[LoopCount]["FirstDay"] = StartHold;

有：

dt.Rows[LoopCount].["FirstDay"] = StartHold;

也許我錯了，但只是想知道，如果說dt.Rows [0 ]包含字段[「FirstDay」]。

來源

2016-03-04 12:41:12

爲什麼我的代碼在數據表中填充單元時停止？

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