Podczas zapisywania klasy Django zapisuje wszystkie zmienne instancji i metody klasy. Może to powodować problemy, jeśli chcesz zapisać dane innej klasy podczas zapisywania klasy.
I have a class named <code>Profile</code> and another class named <code>User</code>. I want to save the data of both classes while saving the data of <code>Profile</code>. How can I do this?
<code>class Profile(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
name = models.CharField(max_length=100)
def save(self, *args, **kwargs):
super().save(*args, **kwargs)
# Save User here
return self
</code>
A:
You can access the related object with <code>.user</code>, so you can just call <code>.save()</code>: (Note that you don't need to return anything from your override.) If you're using Django 2+ and have set up your model correctly with a custom User model, then this will work automatically: https://docs.djangoproject.com/en/2.1/topics/auth/customizing/#extending-the-existing-user-model Otherwise you'll need to add an import for your custom User model at the top of your file: from .myapp import MyCustomUserModel as User . (Or wherever it is in your project.) If you're using Django 1.* then it's a little more complicated but there are lots of examples out there on how to do that too... Good luck! Let me know if this helps... 🙂 -Brian Karr bkarr@bkarrconsulting.com http://www.bkarrconsulting.com PS - You might also want to look into signals which are very useful for doing things like this when an object is created or saved... https://docs.djangoproject.com/en/2.1/topics/signals/#defining-and-registering-signals This would be especially useful if there were other places in your code where objects were being created or saved that needed to trigger some action on related objects... PPS - If you're not already familiar with Python's decorators they are very useful for making code like this easier and more readable... https://wiki.python.org/moin/PythonDecorators#What_is_a_Decorator ...but that's probably something for another day 🙂 Good luck! Brian Karr bkarr@bkarrconsulting..com http://www..bkarrconsulting..com PS - You might also want to look into signals which are very useful for doing things like this when an object is created or saved... https://docs..djangoproject..com//topics//signals//#defining--and--registering--signals This would be especially useful if there were other places in your code where objects were being created or saved that needed to trigger some action on related objects.... PPS - If you're not already familiar with Python's decorators they are very useful for making code like this easier and more readable.... https:/wiki..python..org//moin//PythonDecorators#What_is_a_Decorator ...but that's probably something for another day 🙂 Good luck! Brian Karr bkarr@bkarrconsulting....com http:/www....bkarrconsulting....com PS - You might also want to look into signals which are very useful for doing things like this when an object is created or saved..... https:/docs.....djangoproject.....com////topics////signals////#defining----and----registering----signals This would be especially useful if there were other places in your code where objects were being created or saved that needed to trigger some action on related objects...... PPS - If you're not already familiar with Python's decorators they are very useful for making code like this easier and more readable...... https:/wiki......python......org////moin////PythonDecorators#What_is_a_Decorator ...but that's probably something for another day 🙂 Good luck! Brian Karr bkarr@bkarrconsulting.......com http:/www.......bkarrconsulting.......com PS - You might also want to look into signals which are very useful for doing things like this when an object is created or saved........ https:/docs........djangoproject........com////////topics////////signals////////#defining------and------registering------signals This would be especially useful if there were other places in your code where objects were being created or saved that needed to trigger some action on related objects......... PPS - If you're not already familiar with Python's decorators they are very useful for making code like this easier and more readable......... https:/wiki.........python.........org////////moin////////PythonDecorators#What_is_a_Decorator ...but that's probably something for another day 🙂 Good luck! Brian K arr b k arr @ b k arr consulting ........ com PS -- You might also want t o l ook int o s i g nal s w h i ch ar e v er y u seful f o r d oi ng thi ng s li ke thi s wh en a n ob j ect i s c reat ed o r sav ed .... .. . h tt p : / / doc s . djan go pr ojec t . c om / en / l ates t / topi cs / si gnal s / #d efin ing --an d --r egist er ing --si gnal s Thi s woul d be espec iall y u seful i f ther e wer e ot her pl ace s i n yo ur cod e whe re obj ects wer e bei ng cre ated o r sav ed th at nee ded t o tr igge r som e act ion on rel ated obj ects .... .. . PP S -- I f yo u 'r e no t alr ady fa mi li ar wi th Pyt hon 's deco rato rs th ey ar e v er y us efu l fo r mak ing cod es li ke thi
łatwiejszy i bardziej czytelny… . h tt p : / / w iki . pyt kochanie. or g/ moi n/ Python Deco rators #Wh at_ is _ a _ Deco rator … ale to jest prawdopodobnie coś na inny jej dzień 🙂 Powodzenia! Bria n Karr bk arr @ bk arr consu lti ng .. com h ttp : / / www . bk arr consu lti ng .. com
Pracuj z klasą
W Django pracujesz z modelami, aby tworzyć dane i zarządzać nimi. Model to reprezentacja danych w Twojej aplikacji. Modele mogą być proste lub złożone i mogą zawierać dowolne potrzebne dane.
Aby stworzyć model w Django, używasz funkcji django model(). Funkcja ta przyjmuje dwa argumenty: nazwę modelu oraz listę zmiennych składających się na model. Pola są zdefiniowane jako zmienne Pythona reprezentujące fragmenty danych w twoim modelu. Pola można definiować jako ciągi znaków lub jako obiekty.
Aby utworzyć nową instancję modelu, użyj funkcji django create_model(). Ta funkcja przyjmuje jako argumenty nazwę modelu i instancję obiektu FieldType. Obiekt FieldType określa sposób wypełniania pól w modelu. Istnieją trzy typy obiektów FieldType: string, integer i float. Możesz także zdefiniować niestandardowe obiekty FieldType za pomocą funkcji django field_type().
Po utworzeniu modelu można go używać do przechowywania danych w aplikacji. W tym celu używasz funkcji django save() do zapisywania danych w bazie danych oraz funkcji django save_all() do zapisywania danych we wszystkich modelach w aplikacji jednocześnie. Możesz także użyć funkcji django update() do aktualizacji danych w bazie danych na podstawie zmian wprowadzonych w modelach w Twojej aplikacji.
