Hello, in a meantime while waiting help I managed to solve the problem by me own as follows after heavy testing with various options. Finally all works with Form1 code:
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Me.ParentTableAdapter.Fill(Me.TestiDBDataSet.Parent)
Me.ChildTableAdapter.Fill(Me.TestiDBDataSet.Child)
End Sub
Private Sub ChildBindingNavigatorSaveItem_Click(sender As Object, e As EventArgs) Handles ChildBindingNavigatorSaveItem.Click
Me.Validate()
Me.ChildBindingSource.EndEdit()
Me.TableAdapterManager.UpdateAll(Me.TestiDBDataSet)
End Sub
End Class
It is essential in a form how to select the parent data into a ChildDataGridView- table:
Data (Set column type as DataGridViewCompoBoxColumn)
- DataPropertyName = PickParent
- DataSource = TestiDBDataSet
- DisplayMember = Parent.Parents
- ValueMember = Parent.ID
Appearance: Set DisplayStyle = Nothing
Hope this can be helpfull for any other users with similiar problem.