migrate.erl

is_table_defn_updated() ->
    mnesia:table_info(version1, attributes) =/= record_info(fields, version1).

upgrade_version_table() ->
    case is_table_defn_updated() of 
        false -> ok;
        true -> 
            NewAttrs = record_info(fields, version1),
            { atomic, ok } = mnesia:transform_table(version1, (fun transformer/1), NewAttrs)
    end.

transformer({ version1, Name, Place }) -> #version1{ name = Name, place = Place };
transformer({ version1, Name, Place, _Animal, _Thing }) -> #version1{ name = Name, place = Place }.