I'm learning about ORM, but it's not easy to understand the whole picture. I'm trying to create a "function" or a "filter" linked to my models.py or to PHPmyAdmin to give me a signal when something is changing. I'm making reseachs on signal on django, perhaps a solution to explore.
If you have other informations about ORM or a way to bind the whole thing together. Thanks for your response. Seth On Nov 24, 6:04 pm, "Travis Veazey" <[EMAIL PROTECTED]> wrote: > Seth, > The reason that you don't see the values in u3 change when you change the > database is that the models don't read from the database every time you want > to get a value - that would be silly and would cause Django to be among the > worst-performing frameworks in existence. Database reads take time, and to > avoid that overhead any good ORM will get the values once and then hold them > in memory. > > If you were to modify your database values and then retrieve a new object > (via the filter() method or whatever), you will see your modifications show > up. > > I'm afraid I'm too new to Django to tell you if there's a method to force a > model to refresh its data from the database, but I'm an old hand at ORMs in > general and I know from working with a very poorly-implemented one (this one > would make a separate database call for each field value you wanted to > retrieve; displaying an employee's first, middle, and last names, for > example, would require 3 database queries) that reducing your round-trips to > the database significantly reduces the amount of time required to process > your script (in the example I mentioned, modifying the ORM to make only a > single call to get all the values resulted in reducing page load time by > almost a full third!). > > Hope this gives you some insight. > > -Travis > > On Mon, Nov 24, 2008 at 6:33 AM, Steve Holden <[EMAIL PROTECTED]> wrote: > > > Seth Kaïne wrote: > > > I want to have some more, please. > > > When I do that: > > > >>>> python manage.py shell > > > >>>> from httpbackend.models import Unit > > >>>> Unit.objects.all() > > > > [<Unit: Toto (g.com)>, <Unit: Pingo (s.com)>, <Unit: Titi (p.com)>, > > > <Unit: Jason (f.com)>] > > > >>>> u3 = Unit.objects.filter(id=3)[0] > > >>>> u3.status > > > > <UnitStatus: OFFLINE> > > > ------- I change the status for an ONLINE statement with phpmyadmin in > > > my Table Unit to test if django orm takes modifications to the objet > > > from the DB ------ > > > >>>> u3.status > > > > <UnitStatus: OFFLINE> > > > ------- no, nothing ------- > > > > I want to know why? > > > > And I want to solve this, please! > > > thank you, come again! > > > At the very least you would need to read the database again, as there is > > nothing that would "magically" make the already-in-memory u3 object > > update itself when the database content changes. > > > regards > > Steve --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
