CREATE TABLE Person (name VARCHAR2)
CREATE TABLE PersonFriend (name VARCHAR2, friend VARCHAR2)

Find the name of persons who are friends with Bob.
SELECT T1.name FROM Person AS T1 JOIN PersonFriend AS T2 ON T1.name = T2.name WHERE T2.friend = 'Bob'
SELECT "T1"."name" FROM "Person" "T1" JOIN "PersonFriend" "T2" ON "T1"."name" = "T2"."name" AND "T2"."friend" = 'Bob'