DMZ 1.7.1 (DataMapper OverZealous Edition)

[eluser]TheJim[/eluser]
It looks like you're manually joining them, but where_in_related would do that for you. To answer your question, you shouldn't have to add anything to the join table, you just have to include the Buyer ID in your query.

Also, your code

Code:

foreach ($b as $buyer)
    foreach ($p as $place)
        $buyer->place[] = $place;

will just give you all places for all buyers, not what you want.