如何在数据库中插入多选下拉值，php codeigniter

<form method="post" action="insert.php">
  <select name="options[]" multiple>
    <option value="option1">Option 1</option>
    <option value="option2">Option 2</option>
    <option value="option3">Option 3</option>
  </select>
  <input type="submit" value="Submit">
</form>

<?php
// 获取多选下拉框的值
$options = $this->input->post('options');

// 将多选下拉框的值转换为逗号分隔的字符串
$optionsString = implode(',', $options);

// 将值插入数据库
$data = array(
  'options' => $optionsString
);
$this->db->insert('table_name', $data);
?>