title: Django 1.8 deep reverse relationship lookup
body: <p>I have three models:</p>
  
  <pre><code>class Product(models.Model):
      idproduct=models.AutoField(primary_key=True)
      productname=models.CharField(max_length=100, blank=False, null=False)
      product_state=models.BooleanField(default=True)
  
  
  class ProductInventory(models.Model):
      idinventory=models.AutoField(primary_key=True)
      product_idproduct=models.ForeignKey(Product)
      storage_idstorage=models.ForeignKey(Storage)
  
  class Sale(models.Model):
      idsale=models.AutoField(primary_key=True)
      sale_date = models.DateTimeField(default=timezone.now)
      inventory_idinventory=models.ForeignKey(ProductInventory)
  </code></pre>
  
  <p>What I want to do is to get all the products that has been sold in this month, I have tried this:</p>
  
  <pre><code>thisdate=datetime.today()
  products=Product.objects.filter(product_state=1,productinventory__sale__sale_date__month=thisdate.month).values('pk','productname','productinventory__sale__sale_date')
  </code></pre>
  
  <p>But first, it gives me "nested lookup is not supported" so I taked off the month filter, but after that it gives me a FieldError: <code>Cannot resolve keyword 'sale' into field</code></p>
  
  <p>How can I do this?</p>