如何在 laravel 视图中提高多计数查询的性能

Question

我正在开发一款允许用户向其联系人发送消息的营销应用程序。发送消息时，会创建一个新的 "processed_message" 数据库条目。有一个列表视图显示所有活动以及每个活动发送、阻止和失败的消息数。我的问题是，在有超过 50 个包含大量消息的活动之后，此列表视图加载时间太长。

目前每个活动都有 3 个计算属性（messages_sent、messages_failed 和 messages_blocked），它们都在活动模型的 "appends" 数组中。每个属性查询给定活动的给定类型 processed_messages 的计数。

namespace App;

class Campaign
{
    protected $appends = [
        'messages_sent',
        'messages_blocked',
        'messages_failed'
    ];

    /**
     * @relationship
     */
    public function processed_messages()
    {
        return $this->hasMany(ProcessedMessage::class);
    }

    public function getMessagesSentAttribute()
    {
        return $this->processed_messages()->where('status', 'sent')->count();
    }

    public function getMessagesFailedAttribute()
    {
        return $this->processed_messages()->where('status', 'failed')->count();
    }

    public function getMessagesBlockedAttribute()
    {
        return $this->processed_messages()->where('status', 'blocked')->count();
    }
}

我还尝试一次查询所有消息或分块查询以减少查询次数，但一次获取所有 processed_messages 用于竞选会溢出内存，分块方法也太过分了慢，因为它必须使用偏移量。我考虑过使用 processed_messages 预先加载广告系列，但这显然也会占用太多内存。

namespace App\Http\Controllers;

class CampaignController extends Controller
{
    public function index()
    {
        $start = now();
        $campaigns = Campaign::where('user_id', Auth::user()->id)->orderBy('updated_at', 'desc')->get();
        $ids = $campaigns->map(function($camp) {
            return $camp->id;
        });

        $statistics = ProcessedMessage::whereIn('campaign_id', $ids)->select(['campaign_id', 'status'])->get();
        foreach($statistics->groupBy('campaign_id') as $group) {
            foreach($group->groupBy('status') as $messages) {
                $status = $messages->first()->status;
                $attr = "messages_$status";
                $campaign = $campaigns->firstWhere('id', $messages->first()->campaign_id);
                $campaign->getStatistics()->$attr = $status;
            }
        }

        return view('campaign.index', [
            'campaigns' => $campaigns
        ]);
    }
}

我的主要目标是大大减少当前页面加载时间（当有大量活动时，这可能需要 30 秒到 5 分钟）。

Answer 1

您可以使用 withCount 方法在不加载关系的情况下计算所有对象。

参考：

If you want to count the number of results from a relationship without actually loading them you may use the withCount method, which will place a {relation}_count column on your resulting models.

在你的控制器中你可以这样做：

$count = Campaign::withCount(['processed_messages' => function ($query) {
    $query->where('content', 'sent');
}])->get();

您也可以在同一关系中进行多次计数：

$campaigns = Campaign::withCount([
'processed_messages',
'processed_messages as sent_message_count' => function ($query) {
    $query->where('content', 'sent');
}],
'processed_messages as failed_message_count' => function ($query) {
    $query->where('status', 'failed');
}],
'processed_messages as blocked_message_count' => function ($query) {
    $query->where('status', 'blocked');
}])->get();

您可以通过以下方式访问计数：

echo $campaigns[0]->sent_message_count

Docs

如何在 laravel 视图中提高多计数查询的性能

How to improve performance of multiple count queries in a laravel view

mysql

laravel

laravel-5.7