拉拉威尔复杂关系的形成5

Question

我正在处理一个复杂的购物车项目。我有这样的关系

类别组模型

// AppCategoryGroup
class CategoryGroup extend Model 
{
public function categories()
{
return $this->hasMany(Category::class);
}
}

类别模型

// AppCategory
class Inventory extend Model 
{
public function categoryGroup()
{
return $this->belongsTo(CategoryGroup::class);
}

public function products()
{
return $this->belongsToMany(Product::class);
}

public function listings()
{
return $this->belongsToMany(
Inventory::class, 
'category_product', 
null,
'product_id',
null,
'product_id'
);
}
}

产品型号

// AppProduct
class Product extend Model 
{
public function categories()
{
return $this->belongsToMany(Category::class);
}
public function listings()
{
return $this->hasMany(Inventory::class);
}
}

库存模型

// AppInventory
class Inventory extend Model 
{
public function products()
{
return $this->belongsTo(Product::class);
}
}

现在我陷入了这样一种情况，我需要在分类组和库存模型之间建立一种关系：

// AppCategoryGroup
class CategoryGroup extend Model 
{
public function categories()
{
return $this->hasMany(Category::class);
}

public function listings()
{
// Can't figured out the way
// A belongsToMany like the AppCategory would be great
}
}

有没有一个好的方法来实现这种关系？

Answer 1

Laravel对直接关系没有本地支持。

我为这样的案例创建了一个包：https://github.com/staudenmeir/eloquent-has-many-deep

你可以这样使用它：

class CategoryGroup extends Model {
use StaudenmeirEloquentHasManyDeepHasRelationships;
public function inventories() {
return $this->hasManyDeep(
Inventory::class,
[Category::class, 'category_product', Product::class]
);
}
}