What are all church names?
select name from church
How about church names for weddings of people older than 30?
select t4.name from wedding as t1 join people as t2 on t1.male_id = t2.people_id join people as t3 on t1.female_id = t3.people_id join church as t4 on t4.church_id = t1.church_id where t2.age > 30 or t3.age > 30
What are their opening years?
select t4.name, t4.open_date from wedding as t1 join people as t2 on t1.male_id = t2.people_id join people as t3 on t1.female_id = t3.people_id join church as t4 on t4.church_id = t1.church_id where t2.age > 30 or t3.age > 30