query: SELECT StuID FROM Student EXCEPT SELECT StuID FROM Has_allergy
question: What do be the student ids of student which that ain't ai no allergies?
query_toks: SELECT StuID FROM Student EXCEPT SELECT StuID FROM Has_allergy
query_toks_no_value: select stuid from student except select stuid from has_allergy
question_toks: What do be the student ids of student which that ain't ai no allergies?