php - 如何在 Eloquent 中获取一个属性抛出一个表？

Question

我有属于类别表的子类别表的请求表，那么我如何从请求模型中获取类别的属性？

tables

->requests
id
name
subcategory_id


->subcategories
id
name
category_id


->categories
id
name
color

所以我需要从请求模型中获取颜色，我已经创建了树模型

class Request extends Model
{
    public function user()
    {
        return $this->belongsTo(User::class)->get();
    }

    public function color()
    {
        $somemagicstuff;
        
        return $color;
    }
}

Answer 1

您需要定义您的关系:

# Request.php

class Request extends Model
{  
    public function subcategory()
    {    
        return $this->belongsTo(Subcategory::class);
    }
}

-

# Subcategory.php

class Subcategory extends Model
{  
    public function category()
    {    
        return $this->belongsTo(Category::class);
    }
}

那么你可以这样做:

$color = Request::first()->subcategory->category->color;

当然，您可以将计算属性添加到您的 Request 类以方便访问(请记住，这可能会增加查询的数量):

# Request.php

class Request extends Model
{  
    public function subcategory()
    {    
        return $this->belongsTo(Subcategory::class);
    }

    public function getColorAttribute()
    {    
        return $this->subcategory->category->color;
    }
}

然后:

$color = Request::first()->color;