Accessing models by variable model name in django

Question

I have two identical models, let's say X and Y in django like this:

class X(models.Model):
    con = models.CharField(max_length=100)
    a = models.ForeignField("FOO")

class Y(models.Model):
    con = models.CharField(max_length=100)
    b = models.ForeignField("BAR")

To access an object of these models, I have to use the following code:

models.X.objects.get(
    con = "something",
    a = xy
)

models.Y.objects.get(
    con = "something",
    b = yx
)

Is there a way to set the model name as variable such as model_name = X and then use this code to access the objects:

models.model_name.objects.get(**my_dict)

where

my_dict = {"con":"something", "a":xy}

If you have two identical models may be something wrong with your database schema, and you should move your model name into tables field. — Yevgeniy Shchemelev, Jan 10 '16 at 11:59
The app requires two models because I need two different foreign keys coupled with other fields which are similar but may contain different values. — Keshav Agarwal, Jan 10 '16 at 12:08

RodrigoDela · Accepted Answer · 2016-01-10T11:04:36.973

5

You could do something like this:

getattr(models, model_name).objects.get(**my_dict)

It allows you to access the attributes of models via strings or variables.

edited Jan 10 '16 at 11:04

answered Jan 10 '16 at 10:56

RodrigoDela

1,706
12
26

so basically, what I should do is `getattr(models, X).objects.get(**my_dict)`? – Keshav Agarwal Jan 10 '16 at 11:04
No, `X` should be written as string. So you write `getattr(models, 'X').objects.get(**my_dict)` – RodrigoDela Jan 10 '16 at 11:05

score 3 · Answer 2 · answered Jan 10 '16 at 11:00

You certainly can:

setattr(models, 'model_name', models.X)

This will set the model_name attribute to models.X (or models.Y), which will make your call models.model_name.objects.get(**my_dict) succeed.

Alternatively, you could save the model you want to use in a variable before doing your work and use that from then on:

model_name = models.X
model_name.objects.get(**my_dict)

score 0 · Answer 3 · answered Mar 22 '23 at 17:48

Another way that I used is to use django.apps:

from django.apps import apps
model_name = 'X' # or 'Y'
my_dict = {"con":"something", "a":xy} # as suggested in the problem

model_class = apps.get_model(
  app_label='name_of_app_where_model_is_defined', 
  model_name=model_name
)
model_class.objects.get(**my_dict)

Accessing models by variable model name in django

3 Answers3

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