Public Class Form1
 
    Dim dt1 As New DataTable
    Dim dt2 As New DataTable
 
    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) _
      Handles MyBase.Load
 
        dt1Erstellen()
        dt2Erstellen()
 
        DataGridView1.DataSource = dt2
 
        Dim dr As DataRow
 
        For Each dr In dt1.Rows
            If Not DataRowAuffuellen(dr!Nachname, dr!Wochentag) Then
                DataRowErstellen(dr!Nachname, dr!Wochentag)
            End If
        Next
 
    End Sub
 
    Private Sub dt1Erstellen()
        dt1.Columns.Add("Nachname")
        dt1.Columns.Add("Notes")
        dt1.Columns.Add("Wochentag")
 
        dt1.Rows.Add("Meyer", "Hof fegen", "Montag")
        dt1.Rows.Add("Müller", "Kühe melken", "Dienstag")
        dt1.Rows.Add("Schmidt", "Trecker tanken", "Mittwoch")
        dt1.Rows.Add("Hinz", "Bäuerin melken", "Donnerstag")
        dt1.Rows.Add("Kunz", "Heu ernten", "Freitag")
 
        dt1.Rows.Add("Grün", "Pferd striegeln", "Montag")
        dt1.Rows.Add("Blau", "Pflug anschnallen", "Mittwoch")
 
    End Sub
 
    Private Sub dt2Erstellen()
        dt2.Columns.Add("Montag")
        dt2.Columns.Add("Dienstag")
        dt2.Columns.Add("Mittwoch")
        dt2.Columns.Add("Donnerstag")
        dt2.Columns.Add("Freitag")
    End Sub
 
    Private Function DataRowAuffuellen(ByVal Nachname As String, ByVal _
      Wochentag As String) As Boolean
 
        For Each d As DataRow In dt2.Rows
            If IsDBNull(d(Wochentag)) Then
                d(Wochentag) = Nachname
                Return True
                Exit For
            End If
        Next
 
    End Function
 
    Private Sub DataRowErstellen(ByVal Nachname As String, ByVal Wochentag As _
      String)
 
        Dim dr As DataRow = dt2.NewRow
 
        Select Case Wochentag
            Case "Montag"
                dr!Montag = Nachname
            Case "Dienstag"
                dr!Dienstag = Nachname
            Case "Mittwoch"
                dr!Mittwoch = Nachname
            Case "Donnerstag"
                dr!Donnerstag = Nachname
            Case "Freitag"
                dr!Freitag = Nachname
        End Select
 
        dt2.Rows.Add(dr)
 
    End Sub
 
End Class

EALA FREYA FRESENA