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)
CREATE TABLE Allergy_Type (Allergy VARCHAR2, AllergyType VARCHAR2)

how many students does each advisor have?
SELECT Advisor, COUNT(*) FROM Student GROUP BY Advisor
SELECT "Advisor", COUNT(*) FROM "Student" GROUP BY "Advisor"