Bernd, Glad you managed to achieve what you were after!
Combination of querysets is definitely an obscure part or the ORM API. I couldn't even find a single mention of it in the documentation even if I know it's supported. It might be worth opening a ticket about it if you can't find any mention of it yourself. Best, Simon Le jeudi 15 mars 2018 02:32:18 UTC-4, Bernd Wechner a écrit : > > Simon, > > Thanks enormously. A little experimentation and I got that to work! > Brilliant. Am most pleased it was possible. Good ol' Django to the rescue. > > The thing I got stuck on for a bit was an assertion failure because qs was > DISTINCT and the or'ed qs was not (the or operation raises a rather cryptic > assertion failure then ;-). But nailed it, by examing the SQL and yes, one > contained a DISTINCT clause so I just added it to the other and was happy > ... > > Regards, > > Bernd. > > Simon Charette wrote: > > Hello Bern, > > You're actually pretty close to the solution. > > You should be able to OR an existing querysets filters by using the "|" > operator > between querysets of the same model. That would be the following: > > qs |= Model.objects.filter(Q(...)) > > Simon > > Le mercredi 14 mars 2018 23:45:41 UTC-4, Bernd Wechner a écrit : >> >> Another interesting problem. >> >> Let's say I have a QuerySet which already applies some filters. It's >> provided by a third party library mind you, and all you have is the >> QuerySet instance. >> >> Now I would like to loosen the filter a bit, ad an ORed filter. Not a >> trivial thing it seems. Q objects aren't obviously available unless we can >> extract the Q object for the existing filter. >> >> In code the scenario looks like: >> >> # A Queryset is buillt with some unknown filter criteria >> qs = Model.objects.filter(....) >> # All we see in out code is the QuerySet qs. But we want somehow to add a >> filter criterion. We can do this: >> qs = qs.filter(...) >> # and the new filter criteria will be added, but with AND logic. What if >> we want to add one with OR logic (loosen the filter some) >> # It might look like: >> qs = qs | Q(...) >> # But does it? How can we add an ORed filter criterion to qs? >> >> Basically, there's a chance it's not possible! But if it is, it would >> rely on some syntax for combining chained .filter() methods with an OR >> logic (which seems constrained to Q objects) or extracting the current >> filter from a QuerySet and its constraints as a Q object, so we can OR a >> new constraint to it, and then reapply the filter. >> >> Bit of a mystery to me. >> >> Hoping someone has some insights I'm not getting from the docs here. >> >> Regards, >> >> Bernd. >> >> >> >> >> -- > 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/2BuFFMDL0VI/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > django-users...@googlegroups.com <javascript:>. > To post to this group, send email to django...@googlegroups.com > <javascript:>. > 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/d9d845e5-62c2-479c-83cc-6d21b719a74f%40googlegroups.com > > <https://groups.google.com/d/msgid/django-users/d9d845e5-62c2-479c-83cc-6d21b719a74f%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > > > -- 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 django-users+unsubscr...@googlegroups.com. To post to this group, send email to django-users@googlegroups.com. 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/df7bd805-ee47-4611-b555-2678c02869a1%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
