CREATE TABLE program (program_id DECIMAL, name TEXT, origin TEXT, launch DECIMAL, owner TEXT)
CREATE TABLE broadcast_share (channel_id DECIMAL, program_id DECIMAL, date TEXT, share_in_percent DECIMAL)
CREATE TABLE broadcast (channel_id DECIMAL, program_id DECIMAL, time_of_day TEXT)
CREATE TABLE channel (channel_id DECIMAL, name TEXT, owner TEXT, share_in_percent DECIMAL, rating_in_percent DECIMAL)

find the number of different programs that are broadcast during night time.
SELECT COUNT(DISTINCT program_id) FROM broadcast WHERE time_of_day = 'Night'
SELECT COUNT(DISTINCT "program_id") FROM "broadcast" WHERE "time_of_day" = 'Night'