如何从父文本框中获取FK以在子datagrid中使用

Question

I have two tables tblParent and tblChild with a FK in tblChild. I put these two tables into a dataset and set the relationship to cascade I can put both onto a form and add a parent and child records and then save and all works as it should.

But

I want to use text boxes for the parent not a datagrid. When i DnD the fields and then add a child datagrid the child no longer automatically updates when i save, i get a missing FK exception

Please advise what i need ot do to get the same function as i have with two datagrids.

thanks

John

Answer 1

I've found one way of doing this, it may not be the right way but it does work

In the form load event I have disabled the relationship constraints:

    Me.Dataset.EnforceConstraints = False

then when i come to save:

    Me.TblParentBindingSource.EndEdit()
    Me.TblChildBindingSource.EndEdit()

    Me.TableAdapterManager.UpdateAll(Me.Dataset)
    Me.TblChildTableAdapter.Update(Me.Dataset.tblChild)

after the tableadapter.updateall you can see the fk values propogate in the child datagrid and you can see the childIDs as negatives hence the final update on the child table

I hope this is helpful to someone. If someone can give me a better approach I'd be grateful.

John