让产品与至少一个图像

Question

我的模式是这样的：

class Product(models.Model): 
    name = models.CharField(max_length=100) 
    ... 

class ProductImage(models.Model): 
    thumbnail = models.ImageField(...) 
    ... 
    product = models.ForeignKey(Product, related_name='images', blank=True, null=True) 

我需要改变以下使它只取产品与至少一个图像：

products = Product.objects.filter(status='PU').order_by('?')[:4] 

Answer 1

试试这个：

products = Product.objects.filter(status='PU', images__isnull=False).order_by('?')[:4] 

Answer 2

注释，然后过滤注释。 https://docs.djangoproject.com/en/dev/topics/db/aggregation/

Product.objects.annotate(image_count=Count('images')).filter(image_count__gt=0)