【发布时间】：2015-01-10 21:31:15
【问题描述】：
我很难让 Eloquent 玩得好；我的查询似乎总是有问题。无论如何，我有一个类Item，通过r_item_length 表与Length 具有多对多关系。在数据透视表中，还有一个value 字段。这是Item 模型：
models/db/Item.php：
class Item extends Eloquent implements UserInterface, RemindableInterface {
...
protected $fillable = ['item_singular', 'item_plural'];
public function length()
{
return $this->belongsToMany('Length', 'r_item_length')->withPivot('value');
}
}
我正在尝试从给定Item 的数据透视表中获取value。目前，我正在尝试在我的视图中访问它：
views/db/show.blade.php
<body>
<table>
@foreach ($items as $item)
<tr class="record">
<td>{{ $item->id }}</td>
<td>{{ $item->item_singular }}</td>
<td>{{ $item->item_plural }}</td>
</tr>
<tr>
<td>{{ var_dump($item->length->first()->pivot->value) }}</td>
</tr>
@endforeach
</table>
</body>
$item->length->first()->pivot 是什么给了我错误：“尝试获取非对象的属性”。搜索了几个小时后，看来这种语法应该是可以接受的，$item->length->first()->pivot->value，但我无法让它工作。我也尝试过这种方式，$item->length->pivot->value，但是当然，它不起作用，因为我已经定义了两者之间的多对多关系。
这是否表明我的模型设置方式有问题？我只是查询不正确吗？感谢您的帮助。
下面是var_dump($item->length->first())中第一项的输出。
object(Length)[167]
protected 'table' => string 'length' (length=6)
protected 'hidden' =>
array (size=0)
empty
protected 'fillable' =>
array (size=3)
0 => string 'length_short' (length=12)
1 => string 'length_long_singular' (length=20)
2 => string 'length_long_plural' (length=18)
protected 'connection' => null
protected 'primaryKey' => string 'id' (length=2)
protected 'perPage' => int 15
public 'incrementing' => boolean true
public 'timestamps' => boolean true
protected 'attributes' =>
array (size=6)
'id' => string '2' (length=1)
'length_short' => string 'ft' (length=2)
'length_long_singular' => string 'Foot' (length=4)
'length_long_plural' => string 'Feet' (length=4)
'created_at' => string '2015-01-10 11:00:49' (length=19)
'updated_at' => string '2015-01-10 11:00:49' (length=19)
protected 'original' =>
array (size=9)
'id' => string '2' (length=1)
'length_short' => string 'ft' (length=2)
'length_long_singular' => string 'Foot' (length=4)
'length_long_plural' => string 'Feet' (length=4)
'created_at' => string '2015-01-10 11:00:49' (length=19)
'updated_at' => string '2015-01-10 11:00:49' (length=19)
'pivot_item_id' => string '1' (length=1)
'pivot_length_id' => string '2' (length=1)
'pivot_value' => string '1.2' (length=3)
protected 'relations' =>
array (size=1)
'pivot' =>
object(Illuminate\Database\Eloquent\Relations\Pivot)[172]
protected 'parent' =>
object(Item)[165]
...
protected 'foreignKey' => string 'item_id' (length=7)
protected 'otherKey' => string 'length_id' (length=9)
protected 'guarded' =>
array (size=0)
...
protected 'connection' => null
protected 'table' => string 'r_item_length' (length=13)
protected 'primaryKey' => string 'id' (length=2)
protected 'perPage' => int 15
public 'incrementing' => boolean true
public 'timestamps' => boolean false
protected 'attributes' =>
array (size=3)
...
protected 'original' =>
array (size=3)
...
protected 'relations' =>
array (size=0)
...
protected 'hidden' =>
array (size=0)
...
protected 'visible' =>
array (size=0)
...
protected 'appends' =>
array (size=0)
...
protected 'fillable' =>
array (size=0)
...
protected 'dates' =>
array (size=0)
...
protected 'touches' =>
array (size=0)
...
protected 'observables' =>
array (size=0)
...
protected 'with' =>
array (size=0)
...
protected 'morphClass' => null
public 'exists' => boolean true
protected 'visible' =>
array (size=0)
empty
protected 'appends' =>
array (size=0)
empty
protected 'guarded' =>
array (size=1)
0 => string '*' (length=1)
protected 'dates' =>
array (size=0)
empty
protected 'touches' =>
array (size=0)
empty
protected 'observables' =>
array (size=0)
empty
protected 'with' =>
array (size=0)
empty
protected 'morphClass' => null
public 'exists' => boolean true
【问题讨论】：
-
您是否有可能没有分配
Length的项目？所以$item->length->first()会返回null？ -
:facepalm: 这正是问题所在！我不知道为什么我没有想到。感谢您的帮助。
标签： sqlite laravel laravel-4 eloquent pivot-table