Re: how can I reference a field from one model to another model

Thank Mike Dewhirst is working well

Cheers

On Fri, Jan 25, 2019 at 6:49 AM 'Amitesh Sahay' via Django users <django-users@googlegroups.com> wrote:

hi, 

All the above should work. If you are working on django REST, then you can use ModelSerializer helper function. This will automatically sync with the table fields, and if there are any foreign key and primary key. They would be mapped automatically. 

Regards,

Amitesh Sahay

91-750 797 8619

On Friday, 25 January, 2019, 5:44:04 PM IST, Anirudh Jain <anirudhajain.910@gmail.com> wrote:

You can do this easily by creating creating an object of that model from which you want to get the value or input a value by using 'get_object_or_404' or 'get_list_or_404' by importing from django.shortucts. Reas about these two functions and difference between them in documentation.

Use them, for eg :-

 derive = get_object_or_404(ModelChild1, ModelDad=request.user) #object created of model ModelChild1

access = derive.number #will give the value of number that has been input by user

On Fri, 25 Jan 2019, 17:29 NAveeN Kumar Reddy <knaveenkumarreddy64@gmail.com wrote:

You can use this where you want you to link tables with foreign key

models.ForeignKey(Model_Name,on_delete=models.CASCADE)

That's it  both tables will be in relation after migration of models into database

On Fri, Jan 25, 2019 at 12:20 PM Mike Dewhirst <miked@dewhirst.com.au> wrote:

On 24/01/2019 5:28 pm, carlos wrote:
> Hello,
> I do not know if I'm asking the question correctly, but I need to call
> a field of one model in another model
> example:
> class ModelDad(models.Model):
>     name = blablabla
>
> class ModelChild1(....):
>    fk(ModelDad)
>    number = models.IntegerField()
>
> class ModelChild2(....):
>   fk(ModelDad)
>   another_number = models.IntegerField()
>
>    def make_proces(self):
>       return self.another_number * ModelChild1.number #this is my question
>
> how can I send a call number within the function (make_proces ) of
> ModelChild2

You need a mechanism to find ModelChild1 and the Django ORM provides
Queries for exactly that.

There is a default model manager called 'objects' which you can use to
find instances of models. By that I mean you can pinpoint a row in the
database table which that model represents. For example ... (but to make
it clearer I'll adjust your models above slightly)

class ModelDad(models.Model):
     name = blablabla

class ModelChild1(models.Model):
    dad = models.ForeignKey(ModelDad)
    number = models.IntegerField()

class ModelChild2(models.Model):
    dad = models.ForeignKey(ModelDad)
    another_number = models.IntegerField()

    def make_proces(self):
         child1 = ModelChild1.objects.get(dad=self.dad)
         return self.another_number *child1.number

Visit Django documentation https://docs.djangoproject.com and scroll
down past "First steps" to  "The model layer" and click on a link in the
"Quersets" line. The answers will be in there.

>
> is posible????
>
>
>
> --
> att.
> Carlos Rocha
> --
> 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+unsubscribe@googlegroups.com
> <mailto:django-users+unsubscribe@googlegroups.com>.
> To post to this group, send email to django-users@googlegroups.com
> <mailto: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/CAM-7rO125r3pox%3D137GOfmjnmFaf3cekaNj-j%2B9A0Cwc%3DEM0Fg%40mail.gmail.com
> <https://groups.google.com/d/msgid/django-users/CAM-7rO125r3pox%3D137GOfmjnmFaf3cekaNj-j%2B9A0Cwc%3DEM0Fg%40mail.gmail.com?utm_medium=email&utm_source=footer>.
> 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 django-users+unsubscribe@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/522c40aa-2736-3f57-b23b-9c283c9a59e0%40dewhirst.com.au.
For more options, visit https://groups.google.com/d/optout.

--

Naveen Kumar  Reddy

--
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+unsubscribe@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/CA%2BC2Q82%2Bp47A92koj2%3Djq4aOvFetD%2BEuSikSCSbofTeSxWz-8Q%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 django-users+unsubscribe@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/CAC3mK7exSf7EHZU32OEcoZSb%2BJ1XDyEW0Mz7Prywz8-FYGJAuQ%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 django-users+unsubscribe@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/1747253439.1041432.1548420534962%40mail.yahoo.com.
For more options, visit https://groups.google.com/d/optout.

--

att.

Carlos Rocha

--
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+unsubscribe@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/CAM-7rO0LcQPNzuysCB7iW2C%3D8As2Jn9CDuu%3Dk1zD1JsC4_7RYg%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.