No data exists for the row/column vb.net
<p>Path variable is defined globally.
Values of er.item(0),er.item(1), er.item(2),er.item(2),er.item(3) are not accessible after reader object has used item(0). What is wrong?</p>

<p>here is the code</p>

<p>Private Sub load_qc_by()</p>

<pre><code>    Dim dname = CategoryDropDown2.Text
    con.ConnectionString = path
    cmd.Connection = con
    con.Open()
    cmd.CommandText = "SELECT SQC_By,PQC_By,FQC_By,CQC_By FROM Deliverables WHERE Deliverable ='" &amp; dname &amp; "' AND Project='" &amp; ProjectDropDown2.Text &amp; "'"
    Dim er As OleDbDataReader = cmd.ExecuteReader
    If er.HasRows Then
        While er.Read

            If (er.Item(0).ToString.Equals("NA")) Then
                Call load_all_Names("sqcby_combobox")
                sqcby_combobox.SelectedIndex = 0

            Else
                MessageBox.Show(er.Item(0))
                sqcby_combobox.Text = er.Item(0).ToString
                sqcby_combobox.Enabled = False
            End If

            If (er.Item(1).ToString.Equals("NA")) Then
                Call load_all_Names("pqcby_combobox")
                pqcby_combobox.SelectedIndex = 0
            Else
               MessageBox.Show(er.Item(1))
                pqcby_combobox.Text = er.Item(1)
                pqcby_combobox.Enabled = False
            End If

            If (er.Item(2).ToString.Equals("NA")) Then
                Call load_all_Names("fqcby_combobox")
                fqcby_combobox.SelectedIndex = 0
            Else
                MessageBox.Show(er.Item(2))
                fqcby_combobox.Text = er.Item(2)
                fqcby_combobox.Enabled = False
            End If
            If (er.Item(3).ToString.Equals("NA")) Then
                Call load_all_Names("cqcby_combobox")
                cqcby_combobox.SelectedIndex = 0
            Else
                MessageBox.Show(er.Item(3))
                cqcby_combobox.Text = er.Item(3)
                cqcby_combobox.Enabled = False
            End If
        End While
    End If

        er.Close()
        con.Close()

End Sub
</code></pre>