php - PHP 准备好的语句更新表格

Question

我将把这个问题分成几段以便于参考；

1. 我有一个带有按钮的网站，该按钮将数据库中的当前数字与 1 相加。

2. 我现在使用“更新”表格来添加数据库中的数字。我已经使用准备好的语句来做到这一点：

   <?php
       require_once('connectvars.php');
       $mysqli = new mysqli(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);
   
           if (mysqli_connect_errno()) {
               echo 'Cannot connect.' . mysqli_connect_error(); 
               exit();
               }
   
           if ($stmt = $mysqli->prepare('UPDATE `javascriptbutton` SET `clicks`=? WHERE `id`=?')) { 
   
               $stmt->bind_param('ii', $clicks, $id);
   
               $clicks = $_POST['clicks'] + 1; 
               $id = 1;
   
               $stmt->execute();
   
               $stmt->close();
   
           } else {
               echo 'Woops, something went wrong.: ' . $mysqli->error;
           }
   

   ?>

3. 当用户在 html 中按下一个按钮时，它会调用一个包含 Ajax 的脚本，该脚本引用了上面的 php 脚本。

4. 每次按下按钮时，这个 php 文件都必须从 id=1 的数据库列“clicks”中获取当前的“clicks”，并加上 1 并将其插入数据库。

5. 我一直在研究和查看我的代码，我可以得出结论，它与：

   $clicks = $_POST['clicks'] + 1;

The $_POST['clicks'] should be the current number in the database, and get plussed by 1.

Question: Do I have to create a select form to get the current clicks out of the database? Or how can I plus the current clicks with 1 and put the new number back into the database till next time a person presses the button?

If there are any of the 5 steps you want to deepen, please tell me.

Answer 1

You can just use:

$mysqli->prepare("UPDATE `javascriptbutton` SET `clicks`=`clicks`+1 WHERE `id`=?")

EDIT Full code:

    if ($mysqli->prepare("UPDATE `javascriptbutton` SET `clicks`=`clicks`+1 WHERE `id`=?")) { 

        $stmt->bind_param('i', $id);
        $id = 1;

        $stmt->execute();

        $stmt->close();

    }