Show all people older than 30.
select * from people where age > 30
Show all the weddings of people older than 30.
select * 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 where t2.age > 30 or t3.age > 30
Show the church names for the weddings of all 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