CREATE TABLE PersonFriend (name VARCHAR(255), friend VARCHAR(255)); CREATE TABLE Person (name VARCHAR(255), gender VARCHAR(255))
Find the names of females who are friends with Zach
    
SQL: SELECT T1.name FROM Person AS T1 JOIN PersonFriend AS T2 ON T1.name = T2.name WHERE T2.friend = 'Zach' AND T1.gender = 'female'