Django - Problem with models/manager to organise a query...
- by user296644
Hi,
I have an application to count the number of access to an object for each website in a same database.
class SimpleHit(models.Model):
"""
Hit is the hit counter of a given object
"""
content_type = models.ForeignKey(ContentType)
object_id = models.PositiveIntegerField()
content_object = generic.GenericForeignKey('content_type', 'object_id')
site = models.ForeignKey(Site)
hits_total = models.PositiveIntegerField(default=0, blank=True)
[...]
class SimpleHitManager(models.Manager):
def get_query_set(self):
print self.model._meta.fields
qset = super(SimpleHitManager, self).get_query_set()
qset = qset.filter(hits__site=settings.SITE_ID)
return qset
class SimpleHitBase(models.Model):
hits = generic.GenericRelation(SimpleHit)
objects = SimpleHitManager()
_hits = None
def _db_get_hits(self, only=None):
if self._hits == None:
try:
self._hits = self.hits.get(site=settings.SITE_ID)
except SimpleHit.DoesNotExist:
self._hits = SimpleHit()
return self._hits
@property
def hits_total(self):
return self._db_get_hits().hits_total
[...]
class Meta:
abstract = True
And I have a model like:
class Model(SimpleHitBase):
name = models.CharField(max_length=255)
url = models.CharField(max_length=255)
rss = models.CharField(max_length=255)
creation = AutoNowAddDateTimeField()
update = AutoNowDateTimeField()
So, my problem is this one: when I call Model.objects.all(), I would like to have one request for the SQL (not two). In this case: one for Model in order to have information and one for the hits in order to have the counter (hits_total). This is because I cannot call directly hits.hits_total (due to SITE_ID?). I have tried select_related, but it seems to do not work...
Question:
- How can I add column automatically like (SELECT hits.hits_total, model.* FROM [...]) to the queryset?
- Or use a functional select_related with my models?
I want this model could be plugable on all other existing model.
Thank you,
Best regards.
