codice:
FROM game_category AS c
INNER JOIN show_game AS s ON c.game_category_id = s.game_category_id
INNER JOIN game AS g ON c.game_category_id = g.game_category_id
INNER JOIN question AS q ON g.game_id = q.game_id
WHERE g.game_category_id = s.game_category_id
se

c.pippo = s.pippo
c.pippo = g.pippo

g.pippo e s.pippo sono per forza uguali. A che serve il where?




ultimo quesito ... di tabelle ne puoi anche fare cento, purche' sia logico farle ed evitino dati duplicati.