"John Harcourt" <JohnHarcourt@discussions.microsoft.com> wrote in message
news:8D3047EF-5303-440B-A651-000B0B73BA80@microsoft.com...
>I have a dataset with two data tables. I created a data relation object to
> join the two tables by a common field.
> On a Windows form, I set up the data binding to a combo
> box for the first table. This is the "master". I set up the data binding
> for
> a datagrid for the second table. This is the "detail". When I run it, the
> combo box shows me the list in the combo box correctly, and the data grid
> shows me the child records for the selected item in the combo box
> correctly.
> But when I change the combo box, the grid does not refresh. I added a
> label
> that is bound to the ID and it does change when the combo changes.
>
> What must I do to get the datagrid to update as the combo box updates?
> Thanks for any help!
>
>
> Code, using the Pubs database:
> private void LoadGrid()
> {
> string sqlText = "select * from authors";
> string sqlText2 = "SELECT titleauthor.au_id AS au_id,titles.*
> FROM titleauthor LEFT OUTER JOIN titles ON titleauthor.title_id =
> titles.title_id ORDER BY titleauthor.au_id";
>
> SqlDataAdapter dataAdapter = new SqlDataAdapter(sqlText,
> connection);
> DataSet ds = new DataSet();
> dataAdapter.Fill(ds, "authors");
>
> dataAdapter = new SqlDataAdapter(sqlText2, connection);
> dataAdapter.Fill(ds, "titles");
>
> DataColumn colMaster1 = ds.Tables["authors"].Columns["au_id"];
> DataColumn colDetail1 = ds.Tables["titles"].Columns["au_id"];
>
> DataRelation relation = new DataRelation("AuthorTitles",
> colMaster1, colDetail1);
> ds.Relations.Add(relation);
>
> DataTable dt = ds.Tables["authors"];
>
> cboName.DataSource= dt;
> cboName.DisplayMember="au_lname";
> cboName.ValueMember ="au_id";
>
> lblID.DataBindings.Add("Text", dt, "au_id");
> dataGrid1.SetDataBinding(ds,"authors.AuthorTitles");
> }
>

"PGC" wrote:

> Hi John,
>
> Try binding the datagrid to the "relation". You might want to try using
> BindingSource object also. E.g.
> Dim myBinding1 as new BindingSource
> Dim myBinding2 as new BindingSource
>
> ' fill your ds
>
> myBinding1.DataSource = ds
> myBinding1.DataMember = ds.<authors table>
>
> myCombo.DataSource = myBinding1
> myBinding2.DataSource = myBinding1
> myBinding2.DataMember = ds.Relations.Item(<myRelatrion>)
> myGrid.DataSource = myBinding2
>
> One way of doing it and obviously not tested but you get the idea.
>
> Paul
>
> "John Harcourt" <JohnHarcourt@discussions.microsoft.com> wrote in message
> news:8D3047EF-5303-440B-A651-000B0B73BA80@microsoft.com...
> >I have a dataset with two data tables. I created a data relation object to
> > join the two tables by a common field.
> > On a Windows form, I set up the data binding to a combo
> > box for the first table. This is the "master". I set up the data binding
> > for
> > a datagrid for the second table. This is the "detail". When I run it, the
> > combo box shows me the list in the combo box correctly, and the data grid
> > shows me the child records for the selected item in the combo box
> > correctly.
> > But when I change the combo box, the grid does not refresh. I added a
> > label
> > that is bound to the ID and it does change when the combo changes.
> >
> > What must I do to get the datagrid to update as the combo box updates?
> > Thanks for any help!
> >
> >
> > Code, using the Pubs database:
> > private void LoadGrid()
> > {
> > string sqlText = "select * from authors";
> > string sqlText2 = "SELECT titleauthor.au_id AS au_id,titles.*
> > FROM titleauthor LEFT OUTER JOIN titles ON titleauthor.title_id =
> > titles.title_id ORDER BY titleauthor.au_id";
> >
> > SqlDataAdapter dataAdapter = new SqlDataAdapter(sqlText,
> > connection);
> > DataSet ds = new DataSet();
> > dataAdapter.Fill(ds, "authors");
> >
> > dataAdapter = new SqlDataAdapter(sqlText2, connection);
> > dataAdapter.Fill(ds, "titles");
> >
> > DataColumn colMaster1 = ds.Tables["authors"].Columns["au_id"];
> > DataColumn colDetail1 = ds.Tables["titles"].Columns["au_id"];
> >
> > DataRelation relation = new DataRelation("AuthorTitles",
> > colMaster1, colDetail1);
> > ds.Relations.Add(relation);
> >
> > DataTable dt = ds.Tables["authors"];
> >
> > cboName.DataSource= dt;
> > cboName.DisplayMember="au_lname";
> > cboName.ValueMember ="au_id";
> >
> > lblID.DataBindings.Add("Text", dt, "au_id");
> > dataGrid1.SetDataBinding(ds,"authors.AuthorTitles");
> > }
> >
>
>