Klassi salvestamisel salvestab Django kõik klassi eksemplarimuutujad ja meetodid. See võib põhjustada probleeme, kui soovite kursuse salvestamise ajal salvestada mõne muu klassi andmeid.
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
on kergem ja loetavam … . h tt p : / / w iki . pyt hon. või g/moi n/ Py thon Deco rato rs #Wh at_ on _ a _ Deco rato r … aga tõenäoliselt on see mõni muu tema päev 🙂 Palju õnne! Bria n Karr bk arr @ bk arr consu lti ng .. com h ttp : / / www . bk arr consu lti ng .. com
Töötage klassiga
Djangos töötate oma andmete loomiseks ja haldamiseks mudelitega. Mudel on teie rakenduses olevate andmete esitus. Mudelid võivad olla lihtsad või keerulised ning võivad sisaldada mis tahes tüüpi andmeid, mida vajate.
Djangos mudeli loomiseks kasutate funktsiooni django model(). Sellel funktsioonil on kaks argumenti: mudeli nimi ja mudeli moodustavate väljade loend. Väljad on defineeritud kui Pythoni muutujad, mis esindavad teie mudelis olevaid andmeid. Saate määratleda välju kas stringidena või objektidena.
Mudeli uue eksemplari loomiseks kasutate funktsiooni django create_model(). See funktsioon võtab argumentideks mudeli nime ja FieldType objekti eksemplari. Objekt FieldType määrab, kuidas mudeli väljad tuleks täita. FieldType'i objekte on kolme tüüpi: string, täisarv ja ujuk. Saate määrata ka kohandatud FieldType'i objekte, kasutades funktsiooni django field_type().
Kui olete mudeli loonud, saate seda kasutada andmete salvestamiseks oma rakenduses. Selleks kasutate oma andmebaasi andmete kirjutamiseks funktsiooni django save() ja funktsiooni django save_all() kõigisse rakenduse mudelitesse korraga andmete kirjutamiseks. Saate kasutada ka funktsiooni django update() oma andmebaasis olevate andmete värskendamiseks rakenduse mudelites tehtud muudatuste põhjal.
