php - 计算jQuery upvote插件中的总票数

解决这个问题我真的很困惑。目前我的项目中有一个jQuery upvote插件。因此，每次单击upvote，它都将db中的值保存为true，每次收回投票，它将数据库中的值保存为false，并将另一列中的值保存为0。我所要做的就是像堆栈溢出那样计算投票总数。即使是现在，我对如何解决这个问题仍感到困惑。最后，我用php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--;
     }

 }

我的表格结构：

最佳答案

我认为您应该在数据库端执行此操作，然后像这样重写查询：

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，只需获取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;

关于php - 计算jQuery upvote插件中的总票数，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/49739593/