CREATE TABLE Allergy_Type (Allergy VARCHAR2, AllergyType VARCHAR2)
CREATE TABLE Has_Allergy (StuID NUMBER, Allergy VARCHAR2)
CREATE TABLE Student (StuID NUMBER, LName VARCHAR2, Fname VARCHAR2, Age NUMBER, Sex VARCHAR2, Major NUMBER, Advisor NUMBER, city_code VARCHAR2)

How many students live in each city, and I want to display from low to high by the X.
SELECT city_code, COUNT(*) FROM Student GROUP BY city_code ORDER BY city_code
SELECT "city_code", COUNT(*) FROM "Student" GROUP BY "city_code" ORDER BY "city_code"