Hi All,

I've taken a few steps forward on my project, but got caught by
another problem I can't figure out.  Some help is needed please.

Please read the history of this app.

The application is now working fine,... EXCEPT when I go to add a
child row.  It fails on the "TableAdapter2.Update(DataSet1.Table1)"
line, with the System.Data.OleDb.OleDbException error message:

     "Index or key cannot contain a Null value."

A scaled down version of my add child row routine.

       Dim nxCatRow As DataRow

       ' Add a new Category record
       nxCatRow = DataSet1.Table2.NewRow
       nxCatRow.Item("t2ProdGrp") = tbAddPG.Text
       nxCatRow.Item("t2Cat") = tbAddCat.Text    
       nxCatRow.Item("tt2SubCat") = tbAddSubCat.Text
                 .... fill other fields.....
       DataSet1.Table2.Rows.Add()

       Try
           TableAdapter2.Update(DataSet1.Table1)
       Catch ex As Exception
           MsgBox(ex.ToString, MsgBoxStyle.Exclamation, "Add a  
                         Category Error - Cat Table Update")
       End Try
       DataSet1.Table2.AcceptChanges()

I think I'm mixed up with trying to add to the underlying dataset,
because I'm not going through and using the datarelation source of the
datagridview.  But how do I do it???

Can somebody show me how to overcome this?

Thanks,

Hexman

Here's the History..................................................

I even started off with a new project and a blank form.  In design
view I created a DataSet, 2 tables within the DataSet, 2
TableAdapters, and 2 BindingSources.  One tableadapter and one
BindingSource for each table.  The tables have the following key
structure:

Table1
PK t1Date
pk t1Part
pk t1WH
  t1Cat
  ....other fields.....

Table2
PK t2ProdGrp
pk t2Cat
pk t2SubCat
  ....other fields.....

What I want to do is to scroll thru the items in Table1 and as a row
is selected to show only those rows in Table 2 with a matching
category (t1Cat = t2Cat).

Each row in Table1 has a t1Cat, there may be up to 50 or so Table2
matching Cat's.  (We will manually be assigning sub-cats with this
app.)

In design view, I added a relation "PartsCats", parent key = t1Cat,
child key= t2Cat.

When I run the program, both DataGridViews get loaded and visible, but
no filtering of categories occurs in Table2.  What am I missing?
-------------------------------------------------------------
Ricardo came up with the following answer to my problem:

I only needed to change the last 3 lines using designer for the
binding source and the dgv properties for the DataGridView.  It now
works fine.