Updating hierarchical data

[PontiMax]

I'm working with the Northwind database
tables 'Customers', 'Orders', and 'Order
Details': 'CustomerID' relates 'Orders' to 'Customers',
and 'OrderID' relates 'Order Details' to 'Orders'. For
displaying this hierarchical data I create a DataSet,
append and fill a DataTable for each database table, and
finally set up two Relations.

Say, I want to bind the dataset to a flat DataGrid where
each row consists of the columns 'CompanyName' (from
table 'Customers'), 'OrderDate' (from table 'Orders'),
and 'Quantity' (from table 'Order Details'). The grid
should be editable, i.e. each data modification should be
send back to the database.

Are there any guidelines for implementing this
efficiently? Is it possible to bind datagrid columns to
different DataTables (which in turn belong to the same
DataSet)? How can I retain the relationship between
columns and DataTable items?

Thanks in advance,
PontiMax