I want copy some values to other fields in other table! 2015-07-07 19:34 GMT-03:00 Carlos Andre <[email protected]>:
> i trying use thats solutions, in real yet continuos the problem. > The value, when are to use in other class, return to defaut value without > get the value who i send in the field. > > > 2015-07-07 15:42 GMT-03:00 James Schneider <[email protected]>: > >> On Tue, Jul 7, 2015 at 10:59 AM, Carlos Andre <[email protected]> wrote: >> > example : I have two classes, respectively person contact. >> > I want to contact class has , in its attributes , values worked coming >> from >> > class person , such as name, pass in person , and size of the contact >> name >> > in the class. >> >> Ahh, what you probably want is a foreign key relationship from Contact >> back to Person. See below. >> >> I'm not sure what you mean by size, though. Is that a reference to the >> qtdade field? >> >> > I did something like this : >> > from django.db import models >> > >> > class person ( models.Model ) : >> > qtdade = models.IntegerField (default = 1 ) >> > >> > class Meta : >> > verbose_name_plural = ' Person ' >> > >> > def valor_contato ( self): >> > return self.qtdade * 2 >> > >> > class contact ( models.Model ) : >> > p = Person () >> > value = models.CharField ( max_length = 150, default = p.qtdade ) >> > >> >> What you probably want is this: >> >> class Contact( models.Model ) : >> p = models.ForeignKey(Person, null=False) >> >> >> Note that I used an uppercase letter to start your class (Contact). >> Python classes in general use the CapWords naming convention. See PEP8 >> (https://www.python.org/dev/peps/pep-0008/#class-names). >> >> This makes the Person attributes available via the Contact model >> class, so you can do something like this: >> >> a_person = Person.objects.create(qtdade=3) >> >> a_contact = Contact.objects.create(p=a_person) >> >> print(a_contact.p.qtdade) >> >> ########## >> # Would print out 3 >> ########## >> >> Any attributes that are added to the Person class would then be >> available to a Contact using the syntax I set above. See the >> documentation on relationships between models: >> >> >> https://docs.djangoproject.com/en/dev/topics/db/models/#many-to-one-relationships >> >> As far as this line goes: >> >> > value = models.CharField ( max_length = 150, default = p.qtdade ) >> >> It looks like you are trying to set a default in the model definition >> that is dependent on a field in another model. Django doesn't support >> this because this is a single value that is applied directly in the >> database on the column during a migration/database initialization >> (therefore, no objects exist in order to determine what that value >> should be on a fresh migration). In general, you would set such a >> value inside of the save() method for your model whenever a Contact is >> saved, and use default='' (or default=None, but not recommended for >> CharField fields) in the model definition above. >> >> See this link for more information regarding the save() method on models: >> >> >> https://docs.djangoproject.com/en/dev/topics/db/models/#overriding-predefined-model-methods >> >> > >> > 2015-07-07 4:08 GMT-03:00 James Schneider <[email protected]>: >> >> >> >> Can you give a simple example or analogy of what you are trying to do? >> >> >> >> -James >> >> >> >> On Jul 6, 2015 5:29 PM, "Carlos Andre" <[email protected]> wrote: >> >>> >> >>> Hello to all , I need to solve a problem. I have two classes of which >> >>> have to use , in the second class, the first coming values. How to do >> this? >> >>> Thanks for listening! >> >>> >> >> -- >> 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 http://groups.google.com/group/django-users. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/django-users/CA%2Be%2BciVWhKYeG5jV%2B00epKyOQv2zSJWVq%2BFg-XstRrP%2Bp0mdBg%40mail.gmail.com >> . >> 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/django-users. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/CAA8yBMwGpBQT%2BtA1GqaQRPGxYoP8L1gOYhM87fGFAkBK%2BfLKZg%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
