错误“转换失败时从字符串转换日期和/或时间”

Question

我有休耕SQL查询，也无法获得时的日期值：

String strQuery = @"SELECT TOP 100000" + 
    "[dbo].[Service].[company_name] AS 'Company Name', [dbo].[Service].[status_description] AS 'Status Description'," + 
    "DATEPART(month, [dbo].[Service].[date_entered]) AS 'Month', COUNT([dbo].[Service].[status_description]) AS 'Count'" + 
    "FROM [dbo].[Service] WITH(NOLOCK)" + 
    "WHERE ([dbo].[Service].[status_description] = @Status)" + 

    // **** I used the following to get values from Ajax CalendarExtender 
    // **** (Ajax Format from: yyyy-MM-ddTHH:mm:ss.mmm to: yyyy-MM-ddT23:59:59.000) ******* 
    "AND ([dbo].[Service].[date_entered] BETWEEN '@DateFrom' AND '@DateTo')" + 

    "GROUP BY [dbo].[Service].[company_name], [dbo].[Service].[status_description]," + 
    "DATEPART(month, [dbo].[Service].[date_entered])" + 
    "ORDER BY [dbo].[Service].[status_description] ASC;"; 

    System.Globalization.CultureInfo en = new System.Globalization.CultureInfo("en-US"); 
    SqlConnection con = new SqlConnection(strConnString); 
    SqlCommand cmd = new SqlCommand(strQuery + "", con); 
    cmd.Parameters.AddWithValue("@Status", DdlTickets.SelectedItem.Value); 
    cmd.Parameters.AddWithValue("@DateFrom", TxtDateFrom.Text); 
    cmd.Parameters.AddWithValue("@DateTo", TxtDateTo.Text);   

    SqlDataAdapter da = new SqlDataAdapter(cmd); 
    DataSet ds = new DataSet(); 
    cmd.Connection = con; 
    try 
    { 
     con.Open(); 
     if (DdlTickets.Items.Count > 1) 
     { 
      da.Fill(ds, strQuery); 

      // *** the values come from Ajax, but when It gets to fill the Gridview, it fails with error **** 

      GridView1.DataSource = ds.Tables[strQuery]; 
      GridView1.DataBind(); 
      BtnCSV.Visible = true; 
     } 
     if (GridView1.Rows.Count <= 0) 
     { 
      BtnCSV.Visible = false; 
     } 
     else 
     { 
      //Set Later 
     } 
    } 
    catch (Exception ex) 
    { 
     throw ex; 
    } 
    finally 
    { 
     con.Close(); 
     con.Dispose(); 
    } 

我试图从与该CalendarExtender转换的默认值下面的代码，但它不工作：

cmd.Parameters.AddWithValue("@DateFrom", DateTime.ParseExact(TxtDateFrom.Text, "yyyy-MM-ddTHH:mm:ss.mmm", CultureInfo.InvariantCulture)); 
cmd.Parameters.AddWithValue("@DateTo", DateTime.ParseExact(TxtDateTo.Text, "yyyy-MM-ddTHH:mm:ss.mmm", CultureInfo.InvariantCulture)); 

如果我下面的查询，而不是一个以上，并直接获得价值它的工作原理：

"AND ([dbo].[Service].[date_entered] BETWEEN '2015-04-02T00:00:00.000' AND '2015-09-02T23:59:59.000')" + 

任何可能导致错误的想法？非常感谢您的帮助！

Answer 1

您不需要为参数使用单引号。使用单引号，您的数据库管理器将它们视为string literal而不是参数。

只要删除它们。如果所有东西都不是这样，它就会起作用。

AND ([dbo].[Service].[date_entered] BETWEEN @DateFrom AND @DateTo) 

更多的东西;

• 使用using statement自动处理，而不是手动调用Close或Dispose方法您SqlConnection，SqlCommand和SqlDataAdapter对象。
• 请勿使用AddWithValue方法。 It may generate unexpected and surprising results sometimes。使用Add方法重载来指定您的参数类型及其大小。