query: SELECT Allergy FROM Has_allergy GROUP BY Allergy ORDER BY count(*) DESC LIMIT 1
question: Which allergy has most number of students a-affected?
query_toks: SELECT Allergy FROM Has_allergy GROUP BY Allergy ORDER BY count ( * ) DESC LIMIT 1
query_toks_no_value: select allergy from has_allergy group by allergy order by count ( * ) desc limit value
question_toks: Which allergy has most number of students a-affected?