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)
CREATE TABLE allergy_type (allergy CLOB, allergytype CLOB)

How many students live in each city?
SELECT city_code, COUNT(*) FROM student GROUP BY city_code
SELECT "city_code", COUNT(*) FROM "student" GROUP BY "city_code"