How many people have ever been on the affirmative side of debates?
select count(*) from people where people_id in (select affirmative from debate_people)
Please show their names.
select name from people where people_id in (select affirmative from debate_people)
Please also show the number of times they have been on the affirmative side of debates.
select t2.name, count(*) from debate_people as t1 join people as t2 on t1.affirmative = t2.people_id group by t2.name