Codeigniter SQL备份在本地服务器上工作正常，但在实时显示错误

Question

遇到PHP错误 严重程度：通知

消息：只能通过引用分配变量

**这是我的控制器代码**

public function data_backup()
{
    $this->load->dbutil();
    $prefs = array('format' => 'zip','filename' => 'nirmithi.sql');
    $backup =& $this->dbutil->backup($prefs); 
    $db_name = 'backup-on-'. date("Y-m-d-H-i-s") .'.zip';
    $save = 'Backup/'.$db_name;
    $this->load->helper('file');
    write_file($save, $backup); 
    $this->load->helper('download');
    force_download($db_name, $backup);
}

Answer 1

删除并在此行尝试

$backup = $this->dbutil->backup($prefs);