我想将模型属性预取到 Django 中的查询集。有没有办法做到这一点?
以下是三个模型:
class Place(models.Model):
name = models.CharField(max_length=200, blank=True)
@property
def bestpicurl(self):
try:
return self.placebestpic.picture.file.url
except:
return None
class PlaceBestPic(models.Model):
place = models.OneToOneField(Place)
picture = models.ForeignKey(Picture, on_delete=models.CASCADE)
class Picture(models.Model):
file = ImageField(max_length=500, upload_to="/images/")
我需要类似的东西:
qs = Place.objects.all().select_related('bestpicurl')
任何线索如何做到这一点?谢谢!