CREATE TABLE Student (fname VARCHAR(255), sex VARCHAR(255), StuID VARCHAR(255), Allergy VARCHAR(255)); CREATE TABLE Has_allergy (fname VARCHAR(255), sex VARCHAR(255), StuID VARCHAR(255), Allergy VARCHAR(255))
Find the first name and gender of the student who has allergy to milk but not cat.
    
SQL: SELECT fname, sex FROM Student WHERE StuID IN (SELECT StuID FROM Has_allergy WHERE Allergy = "Milk" EXCEPT SELECT StuID FROM Has_allergy WHERE Allergy = "Cat")