CREATE TABLE Student (StuID NUMBER, LName VARCHAR2, Fname VARCHAR2, Age NUMBER, Sex VARCHAR2, Major NUMBER, Advisor NUMBER, city_code VARCHAR2)
CREATE TABLE Has_amenity (dormid NUMBER, amenid NUMBER)
CREATE TABLE Lives_in (stuid NUMBER, dormid NUMBER, room_number NUMBER)
CREATE TABLE Dorm (dormid NUMBER, dorm_name VARCHAR2, student_capacity NUMBER, gender VARCHAR2)
CREATE TABLE Dorm_amenity (amenid NUMBER, amenity_name VARCHAR2)

How many male students are there in each city? Show a bar chart.
SELECT city_code, COUNT(*) FROM Student WHERE Sex = 'M' GROUP BY city_code
SELECT "city_code", COUNT(*) FROM "Student" WHERE "Sex" = 'M' GROUP BY "city_code"