Question

有没有人知道为什么这个查询会产生一些NULL结果（数组）：

$events = $this->event
    ->with('delegates', 'course')
    ->where('start_date', '<=', $today)
    ->where('active', '1')
    ->where('event_status_id', '!=', '3')
    ->hasCosts()
    ->has('delegates')
    ->get()
    ->map(function($event) {
        foreach ($delegates = $event->delegates()->has('contact')->get() as $delegate) {
            $account = $delegate->contact->account;

            return [
                'company' => $account->company_name,
                'income' => $account->income($delegates),
                'profit' => $account->profit($event, $delegates),
                'event' => $account->eventDetails($event, $delegates)
            ];
        }
    })
    ->toArray();

我已经进入'foreach'循环并为每个事件，帐户，联系人和委托转储了id，并且那里没有NULL结果。我也没有收到错误。

当我转储$ events变量时，我会收到如下输出：

array(8) {
    [0] NULL
    [1] array(4) {
        ["company"] "Razorfish"
        ["income"] 523
        ["profit"] "69.29"
        ["event"] "ITIL® Service Transition Apr 7, 2014 in London (141)"
    }
    [2] array(4) {
        ["company"] "European Central Bank - Europa ECB"
        ["income"] 1332
        ["profit"] "137.33"
        ["event"] "ITIL® Service Offerings & Agreements Apr 7, 2014 in London (142)"
    }
    [3] array(4) {
        ["company"] "Knowledge Pool - KP delegates"
        ["income"] 475
        ["profit"] "-111.75"
        ["event"] "ITIL® Foundation Apr 7, 2014 in Leeds (143)"
    }
    [4] array(4) {
        ["company"] "Plan International/ Plan UK"
        ["income"] 537
        ["profit"] "118.43"
        ["event"] "ITIL® Foundation Apr 14, 2014 in London (144)"
    }
    [5] array(4) {
        ["company"] "Cell Therapy Catapult ( part of Guy's hospital)"
        ["income"] 550
        ["profit"] "-114.75"
        ["event"] "ITIL® Service Design Apr 14, 2014 in London (145)"
    }
    [6] array(4) {
        ["company"] "European Central Bank - Europa ECB"
        ["income"] 597
        ["profit"] "69.80"
        ["event"] "BCS Specialist Certificate in Supplier Management Apr 14, 2014 in London (146)"
    }
    [7] array(4) {
        ["company"] "C Hoare & Co (hoares bank)"
        ["income"] 523
        ["profit"] "97.71"
        ["event"] "ITIL® Continual Service Improvement Apr 23, 2014 in London (148)"
    }
}

注意第一个NULL结果。这只是输出的一个示例，但在实际输出中有许多这样的结果。

为简洁起见，初始查询中的hasCosts（）方法是查询范围函数：

public function scopeHasCosts($query)
{
    return $query->where('tutor_cost', '>', 0)
        ->orWhere('exam_cost', '>', 0)
        ->orWhere('material_cost', '>', 0)
        ->orWhere('venue_cost', '>', 0)
        ->orWhere('notional_cost', '>', 0)
        ->orWhere('buy_price', '>', 0);
}

Answer 1

在map()回调中，您似乎只返回带有联系人的代理的foreach循环的第一次迭代。如果某个事件没有任何具有联系人的代表，则不会返回任何内容 - 因此为空。这是对的吗？

正如文档所述：

map方法遍历集合并传递每个值到给定的回调。回调可以自由修改项目和返回它，从而形成一个新的修改项目集合

因此，您基本上只使用第一个代理的数组结果替换事件集合的每个项目。如果您想要每个事件的联系人的完整列表，那么迭代事件和委托，构建单独的数组可能会更好。这样的事情可能有用：

$events = $this->event
    ->with('delegates', 'course')
    ->where('start_date', '<=', $today)
    ->where('active', '1')
    ->where('event_status_id', '!=', '3')
    ->hasCosts()
    ->has('delegates')
    ->get();

$results = [];

foreach ($events as $event) {
    foreach ($delegates = $events->delegates()->has('contact')->get() as $delegate) {
        $account = $delegate->contact->account;

        $results[] = [
            'company' => $account->company_name,
            'income' => $account->income($delegates),
            'profit' => $account->profit($event, $delegates),
            'event' => $account->eventDetails($event, $delegates)
        ];
    }
}

Answer 2

正如@benJ所提到的，这部分与没有联系人的代表有关。

每个代表通常都有一个联系人，但如果联系人不知道，他们会链接到一个“未知数”表，该表具有唯一的密钥和与之关联的帐户。但有时候，未知数也没有账号。

我修改了查询以执行以下操作：

$events = $this->event
    ->has('delegates')
    ->with('delegates', 'course')
    ->where('start_date', '<=', $today)
    ->where('active', 1)
    ->whereNotIn('event_status_id', [3])
    ->hasCosts()
    ->get()
    ->map(function($event) use ($companies) {
        foreach ($delegates = $event->delegates()->has('contact')->get() as $delegate) {
            $account = $delegate->contact->account;

            return [
                'company' => $account->company_name,
                'account_manager' => $account->user->name(),
                'income' => $account->income($delegates),
                'profit' => $account->profit($event, $delegates),
                'event' => $account->eventDetails($event, $delegates)
            ];
        }

        foreach ($delegates = $event->delegates()->has('unknown')->get() as $delegate) {
            $account = $delegate->unknown->account;

            if ($account) {
                return [
                    'company' => $account->company_name,
                    'account_manager' => $account->user->name(),
                    'income' => $account->income($delegates),
                    'profit' => $account->profit($event, $delegates),
                    'event' => $account->eventDetails($event, $delegates)
                ];
            } else {
                $costPerDelegate = $event->costs() / count($event->delegates);
                $eventVenue = ( ! is_null($event->venue)) ? $event->venue->city : $event->venue_city;
                $eventDetails = ($event->course) ? $event->course->title : 'Unknown Course' . ' ' . $event->start_date->toFormattedDateString() . ' in ' . $eventVenue . ' (' . $event->id . ')';

                return [
                    'company' => 'Unknown',
                    'account_manager' => 'Unknown',
                    'income' => $delegate->price,
                    'profit' => number_format((float) $delegate->price - $costPerDelegate, 2, '.', ''),
                    'event' => $eventDetails
                ];
            }
        }
    })
    ->toArray();

现在返回查询的所有结果。如果有人有更清洁的方式这样做，我很乐意听到它。

我现在必须弄清楚如何根据公司名称合并每个结果，然后为每个公司添加收入/利润，以及在事件下创建一个新数组，列出该公司的事件。

来自Eloquent Query的数组中的NULL结果

2 个答案: