Laravel：过滤嵌套关系？

Question

我不明白为什么这不起作用：

Device::with(['travel.move.position' => function($q) use ($start, $end) {
    return $q->whereBetween('created_date', [$start, $end]);
}]);

我认为它应该给我所有具有travel->move->position 关系的设备，但只有那些position.datetime 介于$start 和$end 之间的设备

我尝试了类似的东西

Device::whereHas('travel.move.position', function($q) use ($start, $end) {
    return $q->whereBetween('created_date', [$start, $end]);
});

我得到了预期的结果，但我没有得到渴望的关系。

为答案 1 添加了查询：

select * 
from `devices` 
where exists (
    select * from `travels` 
    inner join `travel_info` on `travel_info`.`id` = `travels`.`info_id` 
    where `devices`.`id` = `travel_info`.`device_id` 
    and exists (
        select * 
        from `moves` 
        where `moves`.`travel_id` = `travels`.`id` 
        and exists (
            select * from `positions` 
            where `moves`.`position_id` = `positions`.`id` and `created_at`
            between ? and ?
        )
    ) 

查询是完美的（就像 whereHas 一样）但是何时使用 with()：

select `travels`.*, `travel_info`.`device_id` 
from `travels` 
inner join `travel_info` on `travel_info`.`id` = `travels`.`info_id` 
where `travel_info`.`device_id` in (?, ?, ?) 

.... 
select * from `moves` where `moves`.`travel_id` in (?, ..., ?)
....
select * from `positions` where `positions`.`id` in (?, ..., ?)

Answer 1

好的，经过与问题作者的长时间讨论，我们发现问题不在于查询本身，而在于 with() 语句中的关系加载不正确。

我想出了以下查询，它似乎返回了预期的结果。它首先执行一个主查询以获取所有符合过滤条件的设备，然后将相同的过滤器应用于我们需要预先加载的每个关系：

$start = '2016-10-01';
$end = '2016-10-31';

$devices = Device::whereHas('travel.move.position', function($q) use ($start, $end) {
    $q->whereBetween('created_at', [$start, $end]);
})->with([
    'travel' => function($q1) use ($start, $end) {
        $q1->whereHas('move.position', function($q2) use ($start, $end) {
            $q2->whereBetween('created_at', [$start, $end]);
        });
    },
    'travel.move' => function($q1) use ($start, $end) {
        $q1->whereHas('position', function($q2) use ($start, $end) {
            $q2->whereBetween('created_at', [$start, $end]);
        });
    },
    'travel.move.position' => function($q1) use ($start, $end) {
        $q1->whereBetween('created_at', [$start, $end]);
    }
])->get();