Php 访问有说服力的关系属性

我有三个模型，都是一对多关联的。类别、子类别和样式。我的关系是双向的——尽管我似乎在访问相关属性时遇到了问题

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

在我的查询运行之后，我将得到一个样式实例，其中“关系”是子类别的实例，子类别中的“关系”是类别的实例。这是完全正确的

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

问题是我现在似乎无法访问相关的模型实例。例如，如果我打电话：

$style->subcategory->name;

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

我得到“尝试获取非对象的属性”。所以我试着只调用$style->subcategory，结果是'1'

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

为什么$style->subcategory不返回子类别模型的实例？是我遗漏了什么，还是我的理解不正确

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

--编辑--

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

型号

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

类别

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Category extends Eloquent {

    protected $table = 'product_categories';

    protected $fillable = [
            'name',
            'slug',
            'image'
    ];

    public function subcategories() {
            return $this->hasMany('Paragon\Products\Subcategory', 'category');
    }

}

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

表格

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

Paragon\产品\类别

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

ID    ...
1
2

Paragon\产品\子类别

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

ID   Category    ...
1    2
2    2

Paragon\Products\Style

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

ID   Subcategory    ...
1    1
2    1

---

既然样式模型中的subcategory方法应该引用subcategory的单个实例，而不是它们的集合，那么我就不能按我现在（或正在尝试）的方式调用属性了吗？

我在这里是瞎猜。但我将尝试解释如何使用collection以及first和get之间的区别

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

$users= $user-> with('images') -> first(); <-- this is first  row in the table users, each user has many images.
$users-> username; //works;

$users-> images-> image_name; // wont work , model has many ,    
you get error <-- Trying to get property of non-object. 
// access the proprety image and loop through the collection of objects.
$images = $user-> images; // 

foreach ($images as $image){
  echo $image- >image_name; 
}

就你而言

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

$style -> subcategory() -> name;

通过id和子类别获取样式的步骤

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

$style -> with('subcategry') -> where('id', $styleId) -> first();

---

好吧，我想我现在明白了。您的雄辩模型称为子类别，但外键也是。所以当你打电话的时候

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

$style->subcategory

即返回外键而不是模型。要解决此问题，我建议将外键id的名称更改为subcategory_id。如果无法更改数据库，可以通过将方法链接到类似的内容来强制它使用模型

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

$style->subcategory()->first()->name

编辑： 另一个想法是，你可以将关系的名称改为

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

public function subcategory_item()
{
  return $this->belongsTo('Paragon\Products\Subcategory', 'subcategory');
}

那么你应该能够正确地引用它

<?php

namespace Paragon\Products;

use Illuminate\Database\Eloquent\Model as Eloquent;

class Subcategory extends Eloquent {

    protected $table = 'product_subcategories';

    protected $fillable = [
            'category',
            'name',
            'slug',
            'image'
    ];

    public function styles() {
            return $this->hasMany('Paragon\Products\Style', 'subcategory');
    }

    public function category() {
            return $this->belongsTo('Paragon\Products\Category', 'category');
    }

}

$style->subcategory_item->name

---

你是如何质疑这种关系的？在

样式

表中是否有

子类别

列？它可能返回的是该列的值，而不是相关的模型。您确定除了hasMany之外还设置了belongsTo关系吗？您需要向我们展示您的模型，以便我们可以帮助您。@user3158900我知道！这可能就是问题所在。@AdrianFlannery我已经设置好了，请参见上文我正在尝试访问单个模型。样式有一个子类别，但子类别有许多样式。谢谢你的回答