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

find the total percentage share of all channels owned by CCTV.
SELECT SUM(share_in_percent) FROM channel WHERE owner = 'CCTV'
SELECT SUM("share_in_percent") FROM "channel" WHERE "owner" = 'CCTV'