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

A bar chart about what are the average ages for male and female students?, and could you rank by the bars in desc?
SELECT Sex, AVG(Age) FROM Student GROUP BY Sex ORDER BY Sex DESC
SELECT "Sex", AVG("Age") FROM "Student" GROUP BY "Sex" ORDER BY "Sex" DESC NULLS LAST