php - 在 jQuery upvote 插件中计算总票数

Question

解决这个问题我真的很迷茫。目前我的项目中有一个 jQuery upvote 插件。因此，每次我单击 upvote 时，它​​都会将数据库中的值保存为 true，每次收回投票时，它都会将数据库中的值保存为 false，并将另一列中的值保存为 0。我想做的就是就像堆栈溢出一样计算总票数。即使现在我对如何解决这个问题也很困惑。我最终在 php 中编写了这段代码，这也让我的整个程序变慢了:

$sample1 = $this->db->prepare("SELECT * from Ratings WHERE TopicID = :current");
$sample1->bindParam(':current', $id);
$sample1->execute();
$RES1 = $sample1->fetchAll(PDO::FETCH_ASSOC); 
$upVote = 0;

foreach ($RES1 as $mk){
     if(($mk['Upvote'] === 'true') && ($mk['Downvote'] ==='false')){
             $upVote++;
                                    }
     else if(( $mk['Upvote'] ==='false') && ($mk['Downvote'] === 'true')){
             $upVote--;
                                }
     else if(($mk['Upvote'] === 'false') && ($mk['Downvote'] === 'false')){
            $upVote--;
                                }
     else if(($mk['Downvote'] === 'false')){
             $upVote++;
                                }
     else if(($mk['Downvote'] === 'true') && ($mk['Upvote'] ==='0') || ($mk['Upvote'] === 'false')){
             $upVote--;
     }

 }

我的表结构:

Answer 1

我认为您应该在数据库端执行此操作并像这样重写您的查询:

SELECT ((SELECT COUNT(*) FROM Ratings WHERE TopicID = :current AND Upvote = true) - (SELECT COUNT(*) FROM Ratings WHERE TopicID = :current AND Downvote = true)) AS total_votes

在 PHP 端只获取 total_votes:

$sample1 = $this->db->prepare("SELECT ((SELECT COUNT(*) FROM Ratings WHERE TopicID = :current AND Upvote = true) - (SELECT COUNT(*) FROM Ratings WHERE TopicID = :current AND Downvote = true)) AS total_votes");
$sample1->bindParam(':current', $id);
$sample1->execute();
$result = $sample1->fetch(); 
$total_votes = $result->total_votes;