如何使用PHP开发简单的网页计数器

CREATE TABLE `page_views` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `page_url` varchar(255) NOT NULL,
  `view_count` int(11) NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

<?php
// 引入数据库连接配置文件
require_once "config.php";

// 获取当前访问的页面URL
$page_url = $_SERVER['REQUEST_URI'];

// 查询数据库中是否已存在当前页面的访问记录
$query = "SELECT * FROM page_views WHERE page_url = :page_url";
$stmt = $pdo->prepare($query);
$stmt->bindParam(':page_url', $page_url);
$stmt->execute();

if ($stmt->rowCount() > 0) {
    // 如果已存在记录，则更新访问次数
    $row = $stmt->fetch(PDO::FETCH_ASSOC);
    $view_count = $row['view_count'] + 1;
    $query = "UPDATE page_views SET view_count = :view_count WHERE page_url = :page_url";
    $stmt = $pdo->prepare($query);
    $stmt->bindParam(':view_count', $view_count);
    $stmt->bindParam(':page_url', $page_url);
    $stmt->execute();
} else {
    // 如果不存在记录，则插入新的访问记录
    $view_count = 1;
    $query = "INSERT INTO page_views (page_url, view_count) VALUES (:page_url, :view_count)";
    $stmt = $pdo->prepare($query);
    $stmt->bindParam(':page_url', $page_url);
    $stmt->bindParam(':view_count', $view_count);
    $stmt->execute();
}
?>

<?php
$query = "SELECT view_count FROM page_views WHERE page_url = :page_url";
$stmt = $pdo->prepare($query);
$stmt->bindParam(':page_url', $page_url);
$stmt->execute();
$row = $stmt->fetch(PDO::FETCH_ASSOC);
$view_count = $row['view_count'];

echo "该页面已被访问 " . $view_count . " 次";
?>