CREATE TABLE Person (
  name varchar(20) PRIMARY KEY,
  age INTEGER,
  city TEXT,
  gender TEXT,
  job TEXT
)

CREATE TABLE PersonFriend (
  name varchar(20),
  friend varchar(20),
  year INTEGER,
  FOREIGN KEY (name) REFERENCES Person(name),
  FOREIGN KEY (friend) REFERENCES Person(name)
)
SELECT name FROM Person WHERE job  =  'student' AND age  =  (SELECT max(age) FROM person WHERE job  =  'student' )
Who is the oldest person whose job is student?