在 Laravel 中有许多带日期验证的槽

Question

自包含日期以来，我需要重构我的数据关系。我有三个型号：

\App\Product;
discounts()->hasManyThrough('App\Discount', 'App\DiscountProduct', 'product_id','id','id','discount_id');
\App\DiscountProduct;
discount()->belongsTo('App\Discount', 'discount_id');
\App\Discount;
discountProduct()->hasMany('App\DiscountProduct');

discounts_product table: id, discount_id, product_id
折扣table: id, name, start_date, end_date, etc.
产品table：id、名称、价格等

当我打电话给$product->with('discounts') 结果是这样的

{"id": 1,
 "name": "Wild Blue Shirt",
 "discounts": [{
     "method": "per_product",
     "type": "percentage",
     "nominal": 10,
     "start_date": "2018-03-01 16:34:50", <= this is my problem
     "end_date": "2018-03-31 16:34:50", <= this is my problem
      },...other expired discounts],
},...other products

我的问题是：如何筛选每个产品的当前（今天）折扣？

我试过这个：

\App\DiscountProduct;
currentDiscount() {
   return $this->belongsTo("App\Discount", 'discount_id')->whereRaw('now() BETWEEN start_date AND end_date');
};

然后

$product->with('discounts.currentDiscount'); <= doesn't worked

这对我有用：

$product_list = $products->with('variants')->with('discounts')->get();
$product_list->transform(function($product) use ($discounts){
   $data = $product;
   $currentDiscount = collect($product->discounts)->map(function($discount){
       $data = null;
       if($discount['end_date'] > now()){
            $data = $discount;
       };
       return $data;
       });
    $data->currentDiscount = $currentDiscount->filter()->first();
    return $data;
});

但问题是我无法使用 paginate() 功能，使用 forpage()

太痛苦了

否则这个原始数据库也可以工作：

$products = DB::table('products')
->selectRaw("products.id, products.name, products.price, COALESCE(active_discount.discount_amount,0) AS discount")
->leftJoin(DB::raw("(discount_products.product_id, CAST(IF(discounts.`type`='percentage', ROUND((discounts.nominal/100)*products.price,0) ,discounts.nominal) AS UNSIGNED) AS discount_amount FROM discount_products JOIN discounts ON discount_products.discount_id=discounts.id JOIN products ON discount_products.product_id=products.id WHERE NOW() BETWEEN discounts.start_date AND discounts.end_date ) active_discount"),'products.id', '=', 'active_discount.product_id'));

我不认为以上所有方法都是最佳解决方案。请帮忙

Answer 1

我认为您的问题 [pagination/etc] 是因为您发出原始数据库请求而不是使用 Eloquent。

你可以constrain Eager Loading:

Constraining Eager Loads

Sometimes you may wish to eager load a relationship, but also specify additional query constraints for the eager loading query. Here's an example:
$users = App\User::with(['posts' => function ($query) {
    $query->where('title', 'like', '%first%');

}])->get();
In this example, Eloquent will only eager load posts where the post's title column contains the word first. Of course, you may call other query builder methods to further customize the eager loading operation:
$users = App\User::with(['posts' => function ($query) {
    $query->orderBy('created_at', 'desc');

}])->get();

因此，在您的情况下，您可以这样做（尚未测试，但应该可以）：

$product->with(['discounts' => function ($query) {

        $query->where(['start_date' , '<', now()] , ['end_date', '>' , now()]);

        }])->paginate(10);

您也可以在模型中直接在关系中设置它：

public function currentDiscount()
    {
        return $this->belongsTo('App\Discount', 'discount_id')
            ->where(
                ['start_date', '<', now()],
                ['end_date', '>', now()]
            );
    }

在 Laravel 中有许多带日期验证的槽

Has many trough with date verification in Laravel

php

mysql

relational-database

laravel

eloquent

Constraining Eager Loads