How many friendships are there?
select count(*) from personfriend
How many distinct people consider Bob to be their friend?
select count(distinct name) from personfriend where friend = 'Bob'
Who has considered him a friend for the shortest amount of time?
select name from personfriend where friend = 'Bob' order by year
Show the names of everyone who thinks he is their friend.
select name from personfriend where friend = 'Bob'