Question

I am using Django models abstract base class to generate my website menus from the db. My models look like this:

# ABSTRACT MENU 
class Menu(models.Model):
    position = models.IntegerField("Item Position", max_length=2, unique=False)
    title_en = models.CharField("Title (English)", max_length=50)
    title_es = models.CharField("Titulo (Español)", max_length=50)
    url_en = models.URLField("url (English)")
    url_es = models.URLField("url (Español)")       

    def __unicode__(self):
        return self.title_en

    class Meta:
        abstract = True

# top (main) menu ---> inherits from MENU
class MainMenu(Menu):
    class Meta:
        verbose_name_plural = "Menu Items"  

# submenu - for drop downs ---> inherits from MENU
class SubMenu(Menu):
    main_menu = models.ForeignKey(MainMenu, null=True, blank=True)
    class Meta:
        verbose_name_plural = "Sub Menu Items"

Then for the menus I do this:

menu_items = MainMenu.objects.all().select_related().order_by('position')

This is fine, and generates the main menu items ordered by position. However, the submenu items are not ordered. How can I make sure that the submenu items are ordered by position too?

Answer 1

Have you tried defining the order in your model’s Meta class? As long as you are okay with position being the default order in every case it’s not explicitly overridden (which can have performance impacts for large queries) that should remove the need to use .order_by() at all. I haven’t tried this for your specific case, though, so let me know if it doesn’t work.

Edit: also consider looking at order_with_respect_to for related models