запрос в 4 таблицы
получаем список модулей для группы
-- id =1 --
Array ( [id] => 1 [group] => 5 [name] => test5 [gid] => 5 [mid] => 1 [module] => test1 )
Array ( [id] => 2 [group] => 5 [name] => test5 [gid] => 5 [mid] => 2 [module] => test2 )
Array ( [id] => 3 [group] => 5 [name] => test5 [gid] => 5 [mid] => 3 [module] => test3 )-- id =2 --
Array ( [id] => 4 [group] => 4 [name] => test4 [gid] => 4 [mid] => 4 [module] => test4 )
Array ( [id] => 5 [group] => 4 [name] => test4 [gid] => 4 [mid] => 5 [module] => test5 )