Public Class frmComboRelation
 
    Dim ds As New DataSet
    Dim dtmaster As New DataTable
    Dim dtDetail As New DataTable
 
    Dim dtm, dtd As DataTable
 
    Dim bsMaster As New BindingSource
    Dim bsDetail As New BindingSource
 
    Dim cbo As New ComboBox With {.Parent = Me}
 
    Dim dgvDetail As New DataGridView With _
        {.Parent = Me, .AllowUserToAddRows = False, _
         .Top = 50, .Width = 300, .Height = 400}
 
 
    Private Sub frmComboRelation_Load(sender As System.Object, _
                           e As System.EventArgs) Handles MyBase.Load
 
        'Computer-Tabelle
        With dtmaster.Columns
            .Add("ID", GetType(Integer))
            .Add("Computer")
            .Add("SystemID", GetType(Integer))
        End With
 
        With dtmaster.Rows
            .Add(1, "A (Dos)", 2)
            .Add(2, "B (Dos)", 2)
            .Add(3, "C (Unix)", 3)
            .Add(4, "D (Linux)", 1)
            .Add(5, "E (Linux)", 1)
            .Add(6, "F (----)", -1)
        End With
 
        dtmaster.PrimaryKey = {dtmaster.Columns(0)}
        dtmaster.TableName = "Computer"
 
 
        'Tabelle der Betriebssysteme
        dtDetail.Columns.Add("ID", GetType(Integer))
        dtDetail.Columns.Add("System")
        With dtDetail.Rows
            .Add(1, "Linux")
            .Add(2, "Dos")
            .Add(3, "Unix")
            .Add(4, "Windows")
        End With
 
        dtDetail.PrimaryKey = {dtDetail.Columns(0)}
        dtDetail.TableName = "Systeme"
 
 
        'Dataset mit Tabellen
        ds.Tables.AddRange({dtmaster, dtDetail})
 
        'Relation
        ds.Relations.Add(New DataRelation("ComputerSystem", _
            dtmaster.Columns("SystemID"), dtDetail.Columns("ID"), False))
 
 
        'Bindingsourcen für Master-Detail-Beziehung belegen
        bsMaster.DataMember = dtmaster.TableName
        bsMaster.DataSource = ds
 
        bsDetail.DataMember = "ComputerSystem"
        bsDetail.DataSource = bsMaster
 
 
        'Datenbindungen
        cbo.ValueMember = dtmaster.Columns("Computer").ColumnName
        cbo.DataSource = bsMaster
 
        dgvDetail.DataSource = bsDetail       
    End Sub
End Class