>I'm looking for a good way to edit invoice rows.
>
>First I tried to use a grid based on a table with linkmaster,childorder,relationalexpression properties.
>For some strange reason, grid displays all rows, not current invoice.
>
>Second I created a parametrized local view.
>However, invoice row table data does not have primary or candidate key so it is not possible to update it using local view !?
>
>Which is the best way to edit child records in one to many
>relationship?

The best way is to create primary key for your child table too. You may add one more integer field there.