问题描述
非常感谢任何帮助。我有一个日期字段，当运行查询时，它会在达到空值或空值时出错。我是VB的新手，也是Visual Studio中的应用程序。我希望有人能告诉我。我收到错误'myTempCmd = cmd.ExecuteScalar'
代码：
Case DataFields。 SettleDate.DisplayName
Dim SQLTimeout = 120
Dim myTempCon As SqlConnection
myTempCon = New SqlConnection（ConfigurationManager.ConnectionStrings（DT_LoanReport.My.MySettings.DT_ConnectionString）。ConnectionString）
myTempCon.Open（）
Dim myTempCmd As String =
myTempCmd + =SELECT trades.del_date
myTempCmd + =FROM gen as gen WITH（NOLOCK）
myTempCmd + =LEFT外联接交易（NOLOCK）在gen.trade_no = trades.trade_no
myTempCmd + =WHERE
myTempCmd + =gen.trade_no ='+ myDataR eader（trade_no）。ToString.Trim +'
Dim cmd As New SqlCommand（）
cmd.Connection = myTempCon
cmd.CommandText = myTempCmd
'Dim myTempValue As String =
cmd.CommandTimeout = SQLTimeout
试试
myTempCmd = cmd.ExecuteScalar
Catch ex As SqlException
MsgBox（Querry花了太长时间，请再试一次）
myTempCon.Close（ ）
_Value =
退出选择
结束尝试
myTempCon.Close（）
_Value = myTempCmd
Any help would be greatly appreciated. I have a date field that when the query is run, it errors out when it reaches a blank or null value. I am new to VB and the application which is in Visual Studio. I am hoping someone can advise me. I get the error at ' myTempCmd = cmd.ExecuteScalar '
The code:
Case DataFields.SettleDate.DisplayName
Dim SQLTimeout = 120
Dim myTempCon As SqlConnection
myTempCon = New SqlConnection(ConfigurationManager.ConnectionStrings("DT_LoanReport.My.MySettings.DT_ConnectionString").ConnectionString)
myTempCon.Open()
Dim myTempCmd As String = ""
myTempCmd += "SELECT trades.del_date"
myTempCmd += " FROM gen as gen WITH (NOLOCK)"
myTempCmd += " LEFT outer join trades WITH (NOLOCK) on gen.trade_no = trades.trade_no"
myTempCmd += " WHERE "
myTempCmd += " gen.trade_no = '" + myDataReader("trade_no").ToString.Trim + "'"
Dim cmd As New SqlCommand()
cmd.Connection = myTempCon
cmd.CommandText = myTempCmd
'Dim myTempValue As String = ""
cmd.CommandTimeout = SQLTimeout
Try
myTempCmd = cmd.ExecuteScalar
Catch ex As SqlException
MsgBox("The Querry took too long, please try again")
myTempCon.Close()
_Value = ""
Exit Select
End Try
myTempCon.Close()
_Value = myTempCmd
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