>If the user modifies data through the grid, the change will be made to the cursor produced by select-sql, right? My understanding of select-sql in foxpro is that it always has to produce a separate cursor and that it can't be applied to a table without wiping out its contents. It seems it can only be used for viewing data. How can it be used for retrieving, modifying, and saving back to the original destination?

You can retrieve, view and modify cursor records. Saving back to table is up to you: you either use local view cursor with all mechanism available (buffering), or you use regular cursor and write your own transactional or non-transactional code.