I want to do a query on the django User table like this:
u = User.objects.filter(member__in = member_list)
where:
class Member(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
dob = models.DateField('Date of Birth', blank=True, null=True)
and member_list is a list of eligible members.
The query works fine but the problem is I do not actually know the model member is called member. It could be called anything.
I store the name of the model I want in a model called Category. I have a link to the name of the model through content_type.Category is defined as:
class Category(models.Model):
name = models.CharField('Category', max_length=30)
content_type = models.ForeignKey(ContentType)
filter_condition = JSONField(default="{}", help_text=_(u"Django ORM compatible lookup kwargs which are used to get the list of objects."))
user_link = models.CharField(_(u"Link to User table"), max_length=64, help_text=_(u"Name of the model field which links to the User table. 'No-link' means this is the User table."), default="No-link")
def clean (self):
if self.user_link == "No-link":
if self.content_type.app_label == "auth" and self.content_type.model == "user":
pass
else:
raise ValidationError(
_("Must specify the field that links to the user table.")
)
else:
if not hasattr(apps.get_model(self.content_type.app_label, self.content_type.model), self.user_link):
raise ValidationError(
_("Must specify the field that links to the user table.")
)
def __unicode__(self):
return self.name
def _get_user_filter (self):
return str(self.content_type.app_label)+'.'+str(self.content_type.model)+'.'+str(self.user_link)+'__in'
def _get_filter(self):
# simplejson likes to put unicode objects as dictionary keys
# but keyword arguments must be str type
fc = {}
for k,v in self.filter_condition.iteritems():
fc.update({str(k): v})
return fc
def object_list(self):
return self.content_type.model_class()._default_manager.filter(**self._get_filter())
def object_count(self):
return self.object_list().count()
class Meta:
verbose_name = _("Category")
verbose_name_plural = _("Categories")
ordering = ('name',)
So I can retrieve the name of the model that links to User but I then need to convert it into a class which I can include in a query.
I can create an object x = category.content_type.model_class() which gives me <class 'cltc.models.Member'> but when I them perform a query s = User.objects.filter(x = c.category.object_list()) I get the error Cannot resolve keyword 'x' into field.
Any thoughts most welcome.
