django - Multi DB admin

gistfile1.py

from django.contrib import admin
from myapp.models import *

class MultiDBModelAdmin(admin.ModelAdmin):
    using = 'mydb'

    def save_model(self, request, obj, form, change):
        obj.save(using=self.using)

    def queryset(self, request):
        return super(MultiDBModelAdmin, self).queryset(request).using(self.using)

    def formfield_for_foreignkey(self, db_field, request=None, **kwargs):
        return super(MultiDBModelAdmin, self).formfield_for_foreignkey(db_field, request=request, using=self.using, **kwargs)

    def formfield_for_manytomany(self, db_field, request=None, **kwargs):
        return super(MultiDBModelAdmin, self).formfield_for_manytomany(db_field, request=request, using=self.using, **kwargs)
        
class MultiDBTabularInline(admin.TabularInline):
    using = 'mydb'

    def queryset(self, request):
        return super(MultiDBTabularInline, self).queryset(request).using(self.using)

    def formfield_for_foreignkey(self, db_field, request=None, **kwargs):
        return super(MultiDBTabularInline, self).formfield_for_foreignkey(db_field, request=request, using=self.using, **kwargs)

    def formfield_for_manytomany(self, db_field, request=None, **kwargs):
        return super(MultiDBTabularInline, self).formfield_for_manytomany(db_field, request=request, using=self.using, **kwargs)

class my_modelAdmin(MultiDBModelAdmin):
  list_display = ('field1', 'field2','field3',)
  
admin.site.register(my_model, my_modelAdmin)