CREATE TABLE has_allergy (stuid DECIMAL, allergy TEXT)
CREATE TABLE allergy_type (allergy TEXT, allergytype TEXT)
CREATE TABLE student (stuid DECIMAL, lname TEXT, fname TEXT, age DECIMAL, sex TEXT, major DECIMAL, advisor DECIMAL, city_code TEXT)

How many different advisors are listed?
SELECT COUNT(DISTINCT advisor) FROM student
SELECT COUNT(DISTINCT "advisor") FROM "student"