human
Schema:
Person (name, age, city, gender, job)
PersonFriend (name, friend, year)
Please answer with SQL.
assistant
Sure, I understand.
human
Can you list the person names and their friends?
assistant
SELECT name , friend FROM personFriend;
human
Hmm, I want to know which friends are above 40 years old or below 30 years old. | do you mean the name of the person who has friends with age above 40 and under age 30? | I want to know the ages of the friends first, please.
assistant
SELECT T2.friend , T1.age FROM Person AS T1 JOIN PersonFriend AS T2 ON T1.name = T2.friend;
human
Please tell me the names of the person who has friends with age above 40 and under age 30.
assistant
SELECT T1.name FROM Person AS T1 JOIN PersonFriend AS T2 ON T1.name = T2.name WHERE T2.friend IN ( SELECT name FROM Person WHERE age > 40 ) INTERSECT SELECT T1.name FROM Person AS T1 JOIN PersonFriend AS T2 ON T1.name = T2.name WHERE T2.friend IN ( SELECT name FROM Person WHERE age < 30 ) ;