Which exhibition has an attendance more than 100?
select * from exhibition_record as t1 join exhibition as t2 on t1.exhibition_id = t2.exhibition_id where t1.attendance > 100
How about those with an attendance of more than 100 or a ticket price below 10?
select * from exhibition_record as t1 join exhibition as t2 on t1.exhibition_id = t2.exhibition_id where t1.attendance > 100 or t2.ticket_price < 10
How many are there?
select count(*) from exhibition_record as t1 join exhibition as t2 on t1.exhibition_id = t2.exhibition_id where t1.attendance > 100 or t2.ticket_price < 10