Multiple Database in Django

class AuthRouter:
    route_app_labels = {'auth', 'contenttypes', 'sessions', 'admin'}

    def db_for_read(self, model, **hints):
        if model._meta.app_label in self.route_app_labels:
            return 'users_db'
        return None

    def db_for_write(self, model, **hints):
        if model._meta.app_label in self.route_app_labels:
            return 'users_db'
        return None

    def allow_relation(self, obj1, obj2, **hints):
        if (
            obj1._meta.app_label in self.route_app_labels or
            obj2._meta.app_label in self.route_app_labels
        ):
           return True
        return None

    def allow_migrate(self, db, app_label, model_name=None, **hints):
        if app_label in self.route_app_labels:
            return db == 'users_db'
        return None

class Issue:
    route_app_labels = {'issue'}

    def db_for_read(self, model, **hints):
        if model._meta.app_label in self.route_app_labels:
            return 'issue_db'
        return None

    def db_for_write(self, model, **hints):
        if model._meta.app_label in self.route_app_labels:
            return 'issue_db'
        return None

    def allow_migrate(self, db, app_label, model_name=None, **hints):
        if app_label in self.route_app_labels:
            return db == 'issue_db'
        return None

class SecurityEmployee:
    route_app_labels = {'security'}

    def db_for_read(self, model, **hints):
        if model._meta.app_label in self.route_app_labels:
            return 'security_db'
        return None

    def db_for_write(self, model, **hints):
        if model._meta.app_label in self.route_app_labels:
            return 'security_db'
        return None

    def allow_migrate(self, db, app_label, model_name=None, **hints):
        if app_label in self.route_app_labels:
            return db == 'security_db'
        return None

class Automation:
    route_app_labels = {'auto'}

    def db_for_read(self, model, **hints):
        if model._meta.app_label in self.route_app_labels:
            return 'auto_db'
        return None

    def db_for_write(self, model, **hints):
        if model._meta.app_label in self.route_app_labels:
            return 'auto_db'
        return None

    def allow_migrate(self, db, app_label, model_name=None, **hints):
        if app_label in self.route_app_labels:
            return db == 'auto_db'
        return None

DATABASE_ROUTERS = ['routers.db_routers.AuthRouter', 'routers.db_routers.Issue', 'routers.db_routers.SecurityEmployee', 'routers.db_routers.Automation',]

import environ
import os
env = environ.Env()
environ.Env.read_env()

DATABASES = {
    'default': {},
    'users_db': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'users_db_itsupport',
        'USER': env('DATABASE_USER'),
        'PASSWORD': env('DATABASE_PASSWORD'),
        'HOST': env('DATABASE_HOST'),
        'PORT': env('DATABASE_PORT'),
        'OPTIONS': {'charset': 'utf8mb4'},
    },
    'issue_db': {
        'ENGINE': 'django.db.backends.mysql',
        'USER': env('DATABASE_USER'),
        'PASSWORD': env('DATABASE_PASSWORD'),
        'HOST': env('DATABASE_HOST'),
        'PORT': env('DATABASE_PORT'),
        'OPTIONS': {'charset': 'utf8mb4'},
    },
    'security_db': {
        'ENGINE': 'django.db.backends.mysql',
        'USER': env('DATABASE_USER'),
        'PASSWORD': env('DATABASE_PASSWORD'),
        'HOST': env('DATABASE_HOST'),
        'PORT': env('DATABASE_PORT'),
        'OPTIONS': {'charset': 'utf8mb4'},
    },
    'auto_db': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': 'automation_db',
        'USER': env('DATABASE_USER'),
        'PASSWORD': env('DATABASE_PASSWORD'),
        'HOST': env('DATABASE_HOST'),
        'PORT': env('DATABASE_PORT'),
        'OPTIONS': {'charset': 'utf8mb4'},
    },
}

python manage.py makemigrations auto
python manage.py makemigrations security
python manage.py makemigrations issue

python manage.py migrate  --database=auto --fake
python manage.py migrate  --database=security --fake
python manage.py migrate  --database=issue --fake

### Create User
python manage.py migrate
python manage.py createsuperuser --database=users_db

class Device(models.Model):
    class Meta:
        db_table = 'mikrotik_device'  
        
Obj = Device.objects.using('auto_db').all()