Question

This may be a very silly mistake but I just can’t fix it. I have 2 tables, Questions and Questions_Rating.

Questions:

question_id    question            user_id
------------------------------------------
1              'How to blablabla'     1
2              'bla bla bla'          1

Questions_Rating

In this table, users will rate questions either by +1 or -1

question_rating_id   question_id     user_id      rate
------------------------------------------------------
1                         1            2          (+1)
2                         1            3          (+1)
3                         1            4          ( 1)

Now I would simply like to fetch the question from the questions table, and the SUM of the rate in the questions_rating table for this question, which has an ID = 1.

String QUERY = "SELECT q.question, SUM(r.rate) FROM questions q, questions_rating r WHERE  r.question_id = q.question_id AND q.question_id = 1";

And this is what I’m getting.

Column ‘questions.question’ is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

I know that the SUM of the rate will return 1 row, and the question is supposedly 1 row, I can’t figure out what’s wrong with this query.

I am using SQL Server 2008.

Answer 1

You will have to Group the values as per the question so you need a

GROUP BY q.question

at the end of your query

Good Explanation here