Context: CREATE TABLE follows (f1 VARCHAR, f2 VARCHAR); CREATE TABLE user_profiles (uid VARCHAR, name VARCHAR)
Question: Find the id of users who are followed by Mary and Susan.
Answer: SELECT T2.f1 FROM user_profiles AS T1 JOIN follows AS T2 ON T1.uid = T2.f2 WHERE T1.name = "Mary" INTERSECT SELECT T2.f1 FROM user_profiles AS T1 JOIN follows AS T2 ON T1.uid = T2.f2 WHERE T1.name = "Susan"