How to get votes with results with percent calculating - mysql

Question

In my Laravel 5.7/mysql 5 app I have a table with votes results:
`id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
`vote_item_id` INT(10) UNSIGNED NOT NULL,
`user_id` INT(10) UNSIGNED NOT NULL,
`is_correct` TINYINT(1) NOT NULL DEFAULT '0',
`created_at` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
where boolean is_correct field is if answer was correct or incorrect.
I need to get data on percents of correct answers.
Creating such request
$voteItemUsersResultsCorrect = VoteItemUsersResult:: // Grouped by vote name
getByIsCorrect(true)->
getByCreatedAt($filter_voted_at_from, ' > ')->
getByCreatedAt($filter_voted_at_till, ' <= ')->
getByUserId($filterSelectedUsers)->
getByVote($filterSelectedVotes)->
getByVoteCategories($filterSelectedVoteCategories)->
getByVoteIsQuiz(true)->
getByVoteStatus('A')->
select( \DB::raw('count(vote_item_users_result.id) as count, votes.id, votes.name as vote_name') )->
orderBy('vote_name', 'asc')->
groupBy( 'votes.id' )->
groupBy( 'vote_name' )->
join(\DB::raw('vote_items'), \DB::raw('vote_items.id'), '=', \DB::raw('vote_item_users_result.vote_item_id'))->
join(\DB::raw('votes '), \DB::raw('votes.id'), '=', \DB::raw('vote_items.vote_id'))->
get();
I can get number of correct votes with sql request.
SELECT count(vote_item_users_result.id) AS count, votes.id, votes.name AS vote_name
FROM `vote_item_users_result`
INNER JOIN vote_items on vote_items.id = vote_item_users_result.vote_item_id
INNER JOIN votes on votes.id = vote_items.vote_id
WHERE `vote_item_users_result`.`is_correct` = '1' AND vote_item_users_result.created_at > '2018-08-01' AND vote_item_users_result.created_at <= '2018-09-22 23:59:59' AND `votes`.`is_quiz` = '1' AND `votes`.`status` = 'A'
GROUP BY `votes`.`id`, `vote_name`
ORDER BY `vote_name` asc
I know a way to get 2nd similar request with is_correct = '0' and on php side to combine results with percent calculating,
but I wonder if that could be done with eloquent in 1 request?
If yes, how ?
Thanks!

Answer 1

One correct raw MySQL would use conditional aggregation:
SELECT
v.id,
100.0 * COUNT(CASE WHEN vir.is_correct = 1 THEN 1 END) / COUNT(*) AS pct_correct,
100.0 * COUNT(CASE WHEN vir.is_correct = 0 THEN 1 END) / COUNT(*) AS pct_incorrect
FROM votes v
INNER JOIN vote_items vi
ON v.id = vi.vote_id
INNER JOIN vote_item_users_result vir
ON vi.id = vir.vote_item_id
WHERE
vir.created_at > '2018-08-01' AND vir.created_at < '2018-09-23' AND
v.is_quiz = '1' AND
v.status = 'A'
GROUP BY
v.id;
Now we can try writing Laravel code for this:
DB::table('vote')
->select('vote.id',
DB::raw('100.0 * COUNT(CASE WHEN vir.is_correct = 1 THEN 1 END) / COUNT(*) AS pct_correct'),
DB::raw('100.0 * COUNT(CASE WHEN vir.is_correct = 0 THEN 1 END) / COUNT(*) AS pct_incorrect'))
->join('vote_items', 'votes.id', '=', 'vote_items.vote_id')
->join('vote_item_users_result', 'vote_items.id', '=', 'vote_item_users_result.vote_item_id ')
->where([
['vote_item_users_result.created_at', '>', '2018-08-01'],
['vote_item_users_result.created_at', '<', '2018-09-23'],
['vote.is_quiz', '=', '1'],
['vote.status', '=', 'A']
])
->groupBy('vote.id')
->get();