这个不是你的查询的问题，你可以将debug 设置为false，原因是发送或者修改 HTTP 头信息的方法必须在任何输出被输出之前被调用

<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */
namespace yii\web;
use yii\base\Exception;
/**
 * HeadersAlreadySentException represents an exception caused by
 * any headers that were already sent before web response was sent.
 *
 * @author Dmitry Dorogin <dmirogin@ya.ru>
 * @since 2.0.14
 */
class HeadersAlreadySentException extends Exception
{
    /**
     * {@inheritdoc}
     */
    public function __construct($file, $line)
    {
        $message = YII_DEBUG ? "Headers already sent in {$file} on line {$line}." : 'Headers already sent.';
        parent::__construct($message);
    }
}

beforeAction