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

Show all student ids who are older than 20.
SELECT stuid FROM student WHERE age > 20
SELECT "stuid" FROM "student" WHERE "age" > 20