[RESOLVED] VB.net Compare two datatables and return differences

[Fedaykin]

The following will compare two datatables and return the differences. These datatables only have two columns each. Like many of you I had attempted to use the 'merge' method and 'getchanges', but that does not work for the purpose of simply comparing two datatables. I dumped the differences into a DataGridView:

'Datatables are defined in the public space and filled with separate code:
    Dim sdt As New DataTable
    Dim pnpdt As New DataTable
    Dim xdt As New DataTable
'''''''

        Dim xrow As DataRow
        For Each row As DataRow In sdt.Rows
            Dim sdtval As String = row.Item("RefDes")
            Dim Mfr As String = row.Item("Mfr")
            If pnpdt.Rows.Contains(sdtval) = False Then
                xrow = xdt.NewRow
                xrow("RefDes") = sdtval
                xrow("Mfr") = Mfr
                xrow("Notes") = sdtval & "  - Found in sdt, but not found in pnpdt."
                xdt.Rows.Add(xrow)
            End If
        Next

        Dim yrow As DataRow
        For Each rowy As DataRow In pnpdt.Rows
            Dim pnpval As String = rowy.Item("RefDes")
            Dim Mfr As String = rowy.Item("Mfr")
            If sdt.Rows.Contains(pnpval) = False Then
                yrow = xdt.NewRow
                yrow("RefDes") = pnpval
                yrow("Mfr") = Mfr
                yrow("Notes") = pnpval & "  - Found in pnpdt, but not found in sdt."
                xdt.Rows.Add(yrow)
            End If
        Next

        Dim zrow As DataRow
        For Each rowz As DataRow In sdt.Rows
            Dim pnpval As String = rowz.Item("RefDes") 'SMT Ref Des
            If pnpdt.Rows.Contains(pnpval) = True Then

                Dim BMfr As String = rowz.Item("Mfr")
                Dim Prow As DataRow = (From column In pnpdt.Rows Where column("RefDes") = pnpval).First
                Dim PMfr As String = Prow.Item("Mfr")

                If BMfr <> PMfr Then
                    zrow = xdt.NewRow
                    zrow("RefDes") = pnpval
                    zrow("Mfr") = "MISMATCH"
                    zrow("Notes") = pnpval & " - (" & BMfr & ") does not match (" & PMfr & ")."
                    xdt.Rows.Add(zrow)
                End If

            End If
        Next

            DataGridView1.DataSource = xdt
            Dim Cnotes As DataGridViewColumn = Me.DataGridView1.Columns("Notes")
            Cnotes.Width = 500

Could probably be done cleaner, but I hope this helps someone else.