Laravel:一对多对多,检索 distinct() 值 [英] Laravel: One to Many to Many, retrieve distinct() values
问题描述
Laravel 4 项目,使用 Eloquent ORM.
Laravel 4 Project, using Eloquent ORM.
我有三个表:客户、订单和产品(+ 1 个数据透视表 order_product).客户与订单一对多关联.订单与产品多对多关联.
I have three tables: customers, orders and products (+ 1 pivot table order_product). Customers are linked one-to-many to Orders. Orders are linked many-to-many to Products.
Customers 1-->N Orders N<-->N Products
我想在 Customer 模型上有一个方法来检索客户正在购买的产品列表.
I would like to have a method on Customer model that retrieves a list of products that customer is buying.
为了更好地理解这一点,假设产品是消耗品.
To better understand this, assume products are consumable.
例如,客户 #1 可以放置:
For example Customer #1 can place:
- 产品 A、B 和 C 的订单 #1;
- 产品 A、C 和 D 的订单 #2;
- 产品 C 和 E 的订单 #3;
...我要检索的结果是包含产品 A、B、C、D 和 E 的集合.
...and the result I want to retrieve is a Collection with Products A, B, C, D and E.
模型是(动态伪编码):
Models are (pseudo-coded on the fly):
class Product extends Eloquent {
public function orders()
{
return $this->belongsToMany('Order');
}
}
class Orders extends Eloquent {
public function customer()
{
return $this->belongsTo('Customer', 'customer_id');
}
public function products()
{
return $this->belongsToMany('Product');
}
}
class Customers extends Eloquent {
public function orders()
{
return $this->hasMany('Orders', 'customer_id');
}
public function products()
{
// What to put here ???
}
}
推荐答案
感谢@deczo 的回答,我能够提出一个单一的查询方法来检索项目:
Thanks to @deczo's answer, I was able to put up a single query method to retrieve items:
public function items()
{
$query = DB::table('items')->select('items.*')
->join('item_order', 'item_order.component_id', '=', 'items.id')
->leftJoin('orders', 'item_order.order_id', '=', 'orders.id')
->leftJoin('customers', 'customers.id' , '=', 'orders.customer_id')
->where('customers.id', $this->id)
->distinct()
->orderBy('items.id');
$eloquent = new IlluminateDatabaseEloquentBuilder( $query );
$eloquent->setModel( new Item );
return $eloquent->get();
}
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