如何使用foreach通过php和mysql上传多张图片

<form action="upload.php" method="post" enctype="multipart/form-data">
  <input type="file" name="files[]" multiple>
  <input type="submit" value="Upload">
</form>

<?php
// 连接到MySQL数据库
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);

// 处理上传的文件
if(isset($_FILES['files'])){
    $errors = [];
    $uploadedFiles = [];
    $extension = ['jpg', 'png', 'gif'];

    foreach($_FILES['files']['tmp_name'] as $key => $tmp_name){
        $file_name = $_FILES['files']['name'][$key];
        $file_tmp = $_FILES['files']['tmp_name'][$key];
        $file_type = $_FILES['files']['type'][$key];
        $file_size = $_FILES['files']['size'][$key];
        $file_ext = strtolower(end(explode('.', $_FILES['files']['name'][$key])));

        $file = 'uploads/' . $file_name;
        if(in_array($file_ext, $extension) === false){
            $errors[] = 'Extension not allowed: ' . $file_name . ' ' . $file_type;
        }

        if($file_size > 2097152){
            $errors[] = 'File size exceeds limit: ' . $file_name . ' ' . $file_type;
        }

        if(empty($errors)){
            move_uploaded_file($file_tmp, $file);
            $uploadedFiles[] = $file;
            
            // 将上传的图片信息插入到数据库
            $stmt = $conn->prepare("INSERT INTO images (filename, filepath) VALUES (?, ?)");
            $stmt->execute([$file_name, $file]);
        }
    }

    if($errors){
        print_r($errors);
    }

    if($uploadedFiles){
        echo "Files uploaded successfully:";
        foreach($uploadedFiles as $file){
            echo "<br>" . $file;
        }
    }
}
?>