Question

Say I have a Student table, it’s got an int ID. I have a fixed set of 10 multiple choice questions with 5 possible answers. I have a normalized answer table that has the question id, the Student.answer (1-5) and the Student.ID

I’m trying to write a single query that will return all scores over a certain pecentage. To this end I wrote a simple UDF that accepts the Student.answers and the correct answer, so it has 20 parameters.

I’m starting to wonder if it’s better to denormalize the answer table, bring it into my applcation and let my application do the scoring.

Anyone ever tackle something like this and have insight?

Answer 1

If I understand your schema and question correctly, how about something like this:

select student_name, score from students   join (select student_answers.student_id, count(*) as score         from student_answers, answer_key         group by student_id         where student_answers.question_id = answer_key.question_id           and student_answers.answer = answer_key.answer)   as student_scores on students.student_id = student_scores.student_id where score >= 7 order by score, student_name 

That should select the students with a score of 7 or more, for example. Just adjust the where clause for your purposes.