DataReader question

[777axa]

I'm trying to pass a Date value from DB field to a Calendar control using DataReader.

It gives me following error:
++++++++++++++++++++++++++++++++++++++++++++++++++++++
Exception Details: System.InvalidOperationException: No data exists for the row/column.

Source Error:

Line 83: .DataBind()
Line 84: End With
Line 85: calBirthDate.SelectedDate = CDate(dr("BirthDate&quot)
Line 86: 'Response.Write(CDate(dr("BirthDate&quot))
Line 87: End Sub
+++++++++++++++++++++++++++++++++++++++++++++++++++++

Here is the code.
DataGrid - gr displays data just fine
but I can't display the value of the field using response. write (dr.item("BirthDate&quot) - i get the same error


++++++++++++++++++++++++++++++++++++++++++++++++++++++

Private Sub rblEmpl_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rblEmpl.SelectedIndexChanged
Dim strSQL As String
Dim strConn As String
Dim dr As OleDb.OleDbDataReader

strConn = Session("ConnectString&quot
strSQL = "Select EmployeeID, BirthDate FROM Employees where EmployeeID = " & rblEmpl.Items(rblEmpl.SelectedIndex).Value

dr = DataHandler.GetDataReader(strSQL, strConn)

With gr
.DataSource = dr
.DataBind()
End With
calBirthDate.SelectedDate = CDate(dr("BirthDate&quot)

End Sub

 

[Custom24]

Hello -
The datareader returns what is called a firehose cursor (forward only, readonly). When you call the databind method, it moves through the result set past the last record. So you need to read it again. I think this will do the trick.

Private Sub rblEmpl_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rblEmpl.SelectedIndexChanged
Dim strSQL As String
Dim strConn As String
Dim dr As OleDb.OleDbDataReader

strConn = Session("ConnectString&quot
strSQL = "Select EmployeeID, BirthDate FROM Employees where EmployeeID = " & rblEmpl.Items(rblEmpl.SelectedIndex).Value

dr = DataHandler.GetDataReader(strSQL, strConn)

With gr
.DataSource = dr
.DataBind()
End With
dr = DataHandler.GetDataReader(strSQL, strConn)
if dr.read then
calBirthDate.SelectedDate = CDate(dr("BirthDate&quot)
end if

dr.close
End Sub

Note that you should close the datareader.

Hope this works
Mark

 

[777axa]

Thanks Mark,

I'll try dr.read .
I was thinking that having those two lines would be enough:

dr = DataHandler.GetDataReader(strSQL, strConn)
calBirthDate.SelectedDate = CDate(dr("BirthDate&quot)