CREATE TABLE allergy_type (allergy CLOB, allergytype CLOB)
CREATE TABLE has_allergy (stuid NUMBER, allergy CLOB)
CREATE TABLE student (stuid NUMBER, lname CLOB, fname CLOB, age NUMBER, sex CLOB, major NUMBER, advisor NUMBER, city_code CLOB)

What student id corresponds to the oldest student?
SELECT stuid FROM student WHERE age = (SELECT MAX(age) FROM student)
SELECT "stuid" FROM "student" WHERE "age" = (SELECT MAX("age") FROM "student")