Question

I have a Vote-scoring system, each user can score any product each day (maximum of 10 points a day, but they can go on the same product each day).

The schema for my vote table is like so:
Vote: ID, user_id, product_id, score, date.

What I’d like to do is not only fetch the total score and amount of individual votes, (so I can work out an average) but also get the unique amount of voters (DISTINCT user_id’s) in the current time frame (in this example, a month). The current query I have is:

SELECT 
    SUM(`Vote`.`score`) AS `score`,
    COUNT(*) AS `votes`,
    CONCAT(YEAR(`Vote`.`date`), '-', MONTH(Vote.date)) AS `month`
FROM 
    `votes` AS `Vote`
WHERE 
    `product_id` = 4 
GROUP BY 
    month
ORDER BY `Vote`.`date` DESC 

Thanks in advance.

Answer 1

Use COUNT(DISTINCT user_id) in your SELECT list.

You can also have AVG(score) calculated.

SELECT 
    SUM(score) AS totalScore,
    COUNT(*) AS totalVotes,
    COUNT(DISTINCT user_id) AS voters,
    AVG(score) AS averageScore,
    CONCAT(YEAR(`date`), '-', MONTH(`date`)) AS `month`
FROM 
    votes
WHERE 
    product_id = 4 
GROUP BY 
    `month`
ORDER BY `date` DESC