Laravel diff（）之间的Collection返回空数组

Question

我通过返回相同的属性来比较2个集合。预期的结果应该返回1个剩余的用户，我得到的输出是一个空数组。

//110 users
$brand_users = BrandUser::whereSegmentId($campaign->segment_id)
    ->orderBy('brand_user_id', 'ASC')
    ->get(['brand_user_id']);

//109 users

 $campaign_results = \App\CampaignResult::whereCampaignId($campaign_job->campaign_id)
        ->orderBy('brand_user_id', 'ASC')
        ->get(['brand_user_id']);


 $diff = $brand_users->diff($campaign_results);
    return $diff->all();

//output
[] 
//expected
return the remaining brand_user_id

Answer 1

答案是在集合上使用 - ＆gt; pluck（＆＃39; brand_user_id＆＃39;）而不是get（）