UPDATE `groups`
SET city_id = (
    SELECT hotels.city_id
    FROM venues
    JOIN hotels ON venues.hotel_id = hotels.id
    WHERE venues.id = `groups`.venue_id
)
UPDATE `groups`
SET city_id = (
    SELECT hotels.city_id
    FROM venues
    JOIN hotels ON venues.hotel_id = hotels.id
    WHERE venues.id = `groups`.venue_id
)
WHERE EXISTS (
    SELECT 1
    FROM venues
    JOIN hotels ON venues.hotel_id = hotels.id
    WHERE venues.id = `groups`.venue_id
);


venue.hotel.city
city


-upload zip in course
-
