[Answered ]-Multiple Tables for one Django Model

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For a strict requirement, I had to go through this. I will just leave my solution here for future reference.
After User creation, let’s say we want to create a "user_data_100" table with model "UserData" with pgsql database.
Note: here "100" is the "User" model(table entries) primary key value.

in app/model.py create the user model.

from django.db import models
from django.db.models.signals import pre_save, post_save
from django.dispatch import receiver 
from django.db import connection
from django.contrib.auth.models import User


class UserData(models.Model):

    class Meta:
        pass

    dt_column_one = models.CharField(max_length=10,)
    dt_column_two = models.CharField(max_length=5,)

def create_model_by_prototype(model_name, schema_name, tbl_name, prototype):
    import copy
    class Meta:
        pass
    setattr(Meta, "db_table", schema_name + "\".\"" + table_name)
    fields = {}
    for field in prototype._meta.fields:
        fields[field.name] = copy.deepcopy(field)

    attrs = {'__module__': "app.models.models", 'Meta': Meta}
    attrs.update(fields)
    model = type(model_name, (models.Model,), attrs)

    return model

Note: function "create_model_by_prototype" will generate a model with given table name.

Now let’s use the function. I assume the user will get created from the admin site. Let’s create a post_save function to create UserData table.

@receiver(post_save, sender=User)
def create_user_data_table(sender, instance, *args, **kwargs):
print('User post save')

if kwargs['created']: 
    user_id = instance.id
    dy_table_name = "user_data_" + str(user_id)
    model= create_model_by_prototype("MyUserData", "public", dy_table_name, UserData)
    with connection.schema_editor() as schema_editor: schema_editor.create_model(model)
else:
    print('updated')

hope this works for you. Thanks.

👤Naym

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