Laravel - 多对多关系，按产品功能计算产品数量

Question

试图通过其功能（多对多）获取产品数量 例如，

Product::with([’features’])->where(category_id, $category_id)->get();

产品 A->feature1->id

/feature2->id

/feature3->id

产品 B->feature3->id

/feature4->id

/feature6->id

.....

如何从每个功能中获取产品数量（按产品类别过滤后）

我不擅长用文字解释，我尽力了。

最终结果 功能 1 -> 19 个产品 功能 2 -> 5 个产品 ...

Answer 1

试试这个：

Select product_id from products where category_id = "'.$category_id.'" group by feature_id;

Answer 2

您应该在 Product 和 Feature 模型中定义关系

class Product extends Model {
    public function features(){
        return $this->belongsTo(Feature::class);
    }
}

class Feature extends Model {
    public function products(){
        return $this->hasMany(Product::class);
    }
}

我假设每个Product 都有一个属性feature_id，其中包含它所属的Feature 的ID。

$products = Product::with([’features’])->where(category_id, $category_id)->get(); // This query will return list of product

foreach($products as $product){
    // You can access $feature of product like this
    $feature = $product->feature;
}

因为我已经定义了两个模型之间的反向关系，所以我也可以从 Feature 访问 Product。

$feature->products(); // This will return a collection of Product and I can perform any sort of query on that too

// Like count number of Products
$feature->products()->count();
$feature->products()->first(); // get the first product
$feature->products()->last(); // get the last product

以此类推，以此类推

Answer 3

假设您在Feature 模型上有products 关系，您可以试试这个！

$features = Feature::withCount(['products' => function($query){
   $query->where('category_id', $category_id);
}])->get();

您将有一个 products_count 与集合的每条记录。

Answer 4

这样就可以了

   with(['products' => function($q) use($category_id){
                    $q->where('category_id',18);
                }])

                ->find($feature_ids)

                ->groupBy('feature_type_id');