Question

试图通过其功能获得产品数量（多对多）例如，

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

产品A->功能1-> id

/ feature2-> id

/ feature3-> id

产品B->功能3-> id

/ feature4-> id

/ feature6-> id

.....

如何从每个功能中获取产品计数（按产品类别过滤）

我不擅长用语言解释，尽我所能。

最终结果特色1-> 19产品功能2-> 5产品 ...

Answer 1

尝试一下：

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，该属性保存它所属的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

依次类推，等等

Answer 3

假设您在products模型上具有Feature关系，可以尝试一下！

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

对于集合的每个记录，您都会有一个products_count。

Answer 4

这可以解决问题

M[i,j] -> M[n+1-j,i] -> M[n+1-i,n+1-j] -> M[j,n+1-i] -> M[i,j]

Laravel-多对多关系，按产品功能划分的产品数量

4 个答案: