Hi Simon, Thanks for the clarification of the operation of the .union() method - the operative phrase in the docs appears to be "combine the results of two or more QuerySets" - perfect!
My project is currently using 1.8 LTS - I can defer this until I roll forward to 1.11 LTS (hopefully sometime soon). Thanks again, R. On Sat, Jun 3, 2017 at 6:31 PM, Simon Charette <[email protected]> wrote: > Hello Richard, > > Since Django 1.11 you should be able to use the QuerySet.union() method[0] > for that. > > queryset = self.many_field1.order_by('some', 'fields') > combined = queryset.union(self.many_field2.order_by('some', 'fields')) > > Best, > Simon > > [0] https://docs.djangoproject.com/en/1.11/ref/models/querysets/#union > > Le samedi 3 juin 2017 20:20:11 UTC-4, Richard Brockie a écrit : >> >> Hi, >> >> I am combining querysets of the same model in the following manner: >> >> class ExampleModel(models.Model): >> many_field1 = models.ManyToManyField('Model', related_name='name1') >> many_field2 = models.ManyToManyField('Model', related_name='name2') >> >> def combined_many_fields(self): >> qs1 = self.many_field1.all().order_by('some', 'fields') >> qs2 = self.many_field2.all().order_by('some', 'fields') >> >> return qs1 | qs2 >> >> The result of the above code is that the order_by() methods are applied >> after the querysets are combined. This means that the two querysets can >> intermingle. I want them to be sorted before combination, not after, and >> retain being a queryset. >> >> There are ways to force the evaluation of the individual querysets first >> and return a combination in the preferred order. >> >> def combined_many_fields(self): >> >> from itertools import chain >> >> return chain(qs1, qs2) >> >> However, this is no longer a queryset, and therefore cannot be operated >> on with subsequent queryset methods. Is there a way to apply the ordering >> first and retain the queryset nature of the combination? >> >> Am I trying to do something that is outside the scope of a queryset? >> > -- > You received this message because you are subscribed to a topic in the > Google Groups "Django users" group. > To unsubscribe from this topic, visit https://groups.google.com/d/ > topic/django-users/au1f0zHq64M/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To post to this group, send email to [email protected]. > Visit this group at https://groups.google.com/group/django-users. > To view this discussion on the web visit https://groups.google.com/d/ > msgid/django-users/5631ac9b-17a6-401d-9b2b-841440daf7f7%40googlegroups.com > <https://groups.google.com/d/msgid/django-users/5631ac9b-17a6-401d-9b2b-841440daf7f7%40googlegroups.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- R. Richard Brockie Real-time bicycle race results - www.ontheday.net -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/django-users. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/CAKv-vOWukVt%2BbSByuZAxdX4PMSv%2Bh1EVbnEW0tHpCkj7ogBA3A%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
