Question

I have 2 mysql tables :

Question with the following columns : id, question, nranswers

Nranswers must be a number from 1 to 5

And the other table is

Answers with the following columns: questionid, userid, answer .

Now the problem is that I want to get the replies for each answer for one question(id 22 let’s say) .

P.S. If the nranswers is 3, the result should look like this:

(the right number means how many times the reply number was chosen)

1 – 2

2 – 8

3 – 7

If the nranswers is 5, the result should look like this:

1 – 3

2 – 8

3 – 14

4 – 19

5 – 8

Please help me out with the query, atm he’s not counting the answers that weren’t chosen, only the ones that were chosen at least one time.

Answer 1

I took the liberty of adding the question_id column that will be used to join each answer with a question.

Question with the following columns : id, question, nranswers
Answers with the following columns: question_id, userid, answer

Here’s your query:

SELECT answer, COUNT(*) AS answer_count
FROM Answers
GROUP BY answer
WHERE question_id = 22
ORDER by answer

However, if nranswers is 3, but nobody picked 3 as their answer, it won’t show. This query only shows the answers that were chosen.

Edit:

To get a count of all available answers, not just the selected ones, the simplest way (query wise) would be to get rid of the Question.nranswers column and add the table QuestionAnswers:

QuestionAnswers with the following columns: question_id, answer

The data in QuestionAnswers would like this:

quesiton_id answer
-------------------
22          1
22          2
22          3

So, you’d have all the possible answers listed for each question.

The query would then be this:

SELECT qa.answer, COUNT(a.question_id) AS answer_count
FROM QuestionAnswers qa
LEFT OUTER JOIN Answers a
  ON qa.question_id = a.question_id AND a.answer = qa.answer
GROUP BY qa.answer
WHERE qa.question_id = 22
ORDER by qa.answer