Laravel急切的加载似乎不起作用

请参见下图中的数据库关系。

我想显示教室的所有可用小时数（每天9小时），包括该小时的容量和该小时允许的部门，包括排除在教室之外的科目或教室专用的科目。 在show.blade.php中，我构建了一个表，每个表单元格显示一个可用小时。因为这需要两个循环，一个用于白天，一个用于小时，所以我想用关系加载教室。但从完成请求所需的时间（近2秒）和望远镜报告的查询数量来看，无论是否有紧急加载，数据库都会受到质疑

在我的控制器中，我加载如下关系：

$classroom->load('availableHours.allowedDepartments.exclusiveSubjects.subject',
'availableHours.allowedDepartments.excludedSubjects.subject',
'availableHours.allowedDepartments.department');

<!-- loop through all the hours of the day  -->
    @for($i=1;$i<=$maxHour;$i++)
        <tr>
        <td>
        <a href="/classrooms/{{$classroom->number}}/0/{{$i}}/edit">
            {{$i}}
        </a></td>
        <!-- loop through all the days -->
        @foreach($days as $day)
            <!-- show the available hour either in green (available) or red (unavailable)-->
            <td>
            <a href="/classrooms/{{$classroom->number}}/{{$day->id}}/{{$i}}/edit">
                <!-- show the capacity of the hour of the day-->
                {{ $classroom->availableHours()->where([['day_id','=',$day->id],['hour_of_day',$i]] )->first()->capacity }} <br/>

                @foreach($classroom->availableHours()->where([['day_id','=',$day->id],['hour_of_day',$i]] )->first()->allowedDepartments as $allowedDepartment)
                <!-- show the permitted departments along with any exclusive or excluded subjects-->
                {{$allowedDepartment->department->name}}
                @foreach ($allowedDepartment->exclusiveSubjects as $subjectDepartment)
                    {{$subjectDepartment->subject->code}}
                @endforeach
                 <br/>
                @endforeach
            </a></td>
        @endforeach
        </tr>
    @endfor

如果我扔掉教室，关系就会被加载。在我的show.blade.php中，我循环使用可用的小时，如下所示：

$classroom->load('availableHours.allowedDepartments.exclusiveSubjects.subject',
'availableHours.allowedDepartments.excludedSubjects.subject',
'availableHours.allowedDepartments.department');

<!-- loop through all the hours of the day  -->
    @for($i=1;$i<=$maxHour;$i++)
        <tr>
        <td>
        <a href="/classrooms/{{$classroom->number}}/0/{{$i}}/edit">
            {{$i}}
        </a></td>
        <!-- loop through all the days -->
        @foreach($days as $day)
            <!-- show the available hour either in green (available) or red (unavailable)-->
            <td>
            <a href="/classrooms/{{$classroom->number}}/{{$day->id}}/{{$i}}/edit">
                <!-- show the capacity of the hour of the day-->
                {{ $classroom->availableHours()->where([['day_id','=',$day->id],['hour_of_day',$i]] )->first()->capacity }} <br/>

                @foreach($classroom->availableHours()->where([['day_id','=',$day->id],['hour_of_day',$i]] )->first()->allowedDepartments as $allowedDepartment)
                <!-- show the permitted departments along with any exclusive or excluded subjects-->
                {{$allowedDepartment->department->name}}
                @foreach ($allowedDepartment->exclusiveSubjects as $subjectDepartment)
                    {{$subjectDepartment->subject->code}}
                @endforeach
                 <br/>
                @endforeach
            </a></td>
        @endforeach
        </tr>
    @endfor

@对于（$i=1；$i）
@foreach（$天作为$天）
当您调用
$choork->availableHours（）
时，实际上是再次查询关系函数并返回它，而不是访问已经存在的函数

在控制器中加载关系后，对象将被包含所需值的属性填充。因此，在加载后，请改用
$kitcher->availableHours
。（与
$allowedDepartment->exclusiveSubjects类似）