CREATE TABLE happy_hour_member (hh_id DECIMAL, member_id DECIMAL, total_amount DECIMAL)
CREATE TABLE member (member_id DECIMAL, name TEXT, membership_card TEXT, age DECIMAL, time_of_purchase DECIMAL, level_of_membership DECIMAL, address TEXT)
CREATE TABLE happy_hour (hh_id DECIMAL, shop_id DECIMAL, month TEXT, num_of_shaff_in_charge DECIMAL)
CREATE TABLE shop (shop_id DECIMAL, address TEXT, num_of_staff TEXT, score DECIMAL, open_year TEXT)

which shop has happy hour most frequently? List its id and number of happy hours.
SELECT shop_id, COUNT(*) FROM happy_hour GROUP BY shop_id ORDER BY COUNT(*) DESC LIMIT 1
SELECT "shop_id", COUNT(*) FROM "happy_hour" GROUP BY "shop_id" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1