CREATE TABLE person (name CLOB, age NUMBER, city CLOB, gender CLOB, job CLOB)
CREATE TABLE personfriend (name CLOB, friend CLOB, year NUMBER)

Who is the oldest person whose job is student?
SELECT name FROM person WHERE job = 'student' AND age = (SELECT MAX(age) FROM person WHERE job = 'student')
SELECT "name" FROM "person" WHERE "age" = (SELECT MAX("age") FROM "person" WHERE "job" = 'student') AND "job" = 'student'