Hi, Note that Django querysets are lazy.
So running: qs1 = MyModel.objects.all() As is, doing that doesn't execute any queries. If you want filtered objects, just add filter: qs2 = qs1.filter(color="blue") qs2 is not even evaluated yet. You need actually cause something that evaluates queryset. But if you want to fetch all objects from qs1 and then apply some "filtering" you can just evaluate whole queryset and it's results will be cached. You can use list comprehensions or itertools to filter your objects in Python. On Mon, Mar 18, 2019 at 2:16 PM Thomas Klopf <thomas.kl...@gmail.com> wrote: > Hello, > Yes exactly that, if mo1 is in qs2. BUT without running the SQL on the > database, if possible. > > Thanks! > Tom > > > On Friday, March 15, 2019 at 1:34:34 PM UTC+1, jgi...@caktusgroup.com > wrote: >> >> Tom, >> >> Could you clarify "fits into"? >> >> qs1 = Table.objects.all() >> qs2 = Table.objects.filter(color='blue') >> >> >> mo1 = qs1[0] >> >> >> Are you trying to determine if mo1 is in qs2? >> >> Best >> >> On Friday, March 15, 2019 at 7:46:14 AM UTC-4, Thomas Klopf wrote: >>> >>> Hi all, >>> Please I have a question, couldn't find any answer for it.. >>> >>> Let's say I have 2 QuerySets: >>> 1) Select all records from table >>> 2) Select all records from table where color = "blue" >>> >>> So QuerySet #2 is more restricted than QuerySet #1 >>> >>> So question is - if I get a model object from QuerySet #1, is it >>> possible to check if the model object is 'filtered' or fits into QuerySet >>> #2, without actually executing the SQL for QuerySet #2 to find the record >>> again? >>> >>> I'm asking because running the SQL for QuerySet #2 is expensive, ideally >>> would test if the record fits into the QuerySet in purely python/django. >>> >>> Thanks in advance! >>> Tom >>> >>> -- > 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/a09cf16e-8f9c-4bf0-b382-708ba21d28bd%40googlegroups.com > <https://groups.google.com/d/msgid/django-users/a09cf16e-8f9c-4bf0-b382-708ba21d28bd%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- Jani Tiainen Software wizard https://blog.jani.tiainen.cc/ Always open for short term jobs or contracts to work with Django. -- 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/CAHn91oeVhEmC2kGeGmHYjRcq1KJJvhxwbUBEyHv8zdriHDF1eQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
