One way to do this is to create views for the child grid.
This is what I am doing in the GDD system. You can then add index to the view and also filter. It is the best way to do child grid.

For your problem with check box, verify if you are the Column.sparse property at .f.

>Hi all,
>
>I have a parent grid with to child related grids in 1 form in VFP7.
>
>1) If I DON'T use the data environment (manually open my files) or I use DE with the one-to-many relation property set to OFF, my checkboxes in the child grids make my record pointer go to the bottom of the grid when they get the focus.
>
>2) If I DO use the data environment with the one-to-many relation property set to ON, my checkbox problem is fixed but I get duplicates records in the parent grid, i.e. as many copies as I have children records.
>
>I have no code in my checkbox class (I even tried the checkbox base control).
>
>TIA for your help.