如何让用户使用PHP和MySQL添加多个标签？

<form action="add_tags.php" method="post">
  <div id="tags-container">
   <input type="text" name="tags[]" placeholder="标签1">
  </div>
 <button type="button" onclick="addTag()">添加标签</button>
 <button type="submit">提交</button>
</form><script>
  function addTag() {
    const container = document.getElementById('tags-container');
    const input = document.createElement('input');
    input.type = 'text';
    input.name = 'tags[]';
    input.placeholder = `标签${container.children.length + 1}`;
    container.appendChild(input);
  }
</script>

<?php
// 连接到数据库
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

$conn = new mysqli($servername, $username, $password, $dbname);

// 检查连接
if ($conn->connect_error) {
  die("连接失败: " . $conn->connect_error);
}

// 获取标签数组
$tags = $_POST['tags'];

// 将标签数组转换为逗号分隔的字符串
$tags_str = implode(',', $tags);

// 插入标签到数据库
$sql = "INSERT INTO tags (tags) VALUES ('$tags_str')";

if ($conn->query($sql) === TRUE) {
  echo "标签已成功添加";
} else {
  echo "Error: " . $sql . "<br>" . $conn->error;
}

$conn->close();
?>