Can "list_display" in a Django ModelAdmin display attributes of ForeignKey fields?

python

django-admin

select_related

prefetch_related

byNikita Barsukov·Nov 17, 2024

For displaying a ForeignKey attribute in list_display of a Django Admin, you need to define a callable method that returns the attribute and include it in list_display.

Say, you have a Book model possessing a foreign key to an Author model. To show the author's name in list_display, here's how to do it:

class BookAdmin(admin.ModelAdmin):
    list_display = ('title', 'author_name')

    def author_name(self, obj):
        # Heck of a name for a method, ain't it? 😃
        return obj.author.name
    author_name.short_description = 'Author Name'

This author_name method grabs the name of every book's associated author, and labels the unleashed magic as "Author Name" in the admin dashboard.

Streamlining performance with `select_related`

A performance-oriented tip: enhance your admin interface using select_related. Here's how select_related can reduce number of SQL queries and walkthrough the forest of data in an optimized fashion:

class BookAdmin(admin.ModelAdmin):
    list_display = ('title', 'author_name')

    def get_queryset(self, request):
        qs = super().get_queryset(request)
        # SQL sparing some pain in joins, thank you - "select_related"!
        return qs.select_related('author')

    def author_name(self, obj):
        return obj.author.name
    author_name.short_description = 'Author Name'
    author_name.admin_order_field = 'author__name'  # Make this column sortable

Advanced customization

Diving deep in ForeignKey relations

Chaining attributes in a callable method allow us to access attributes of more complex relationships or deeper foreign keys:

def publisher(self, obj):
    # Careful here! That's one deep dive!
    return obj.author.publisher.name
publisher.short_description = 'Publisher'
publisher.admin_order_field = 'author__publisher__name'  # Sortable, because why not?

Tackling ManyToMany with `prefetch_related`

For scenarios involving ManyToMany relationships or reverse foreign keys, reach for prefetch_related. prefetch_related fetches related objects in a separate query, helping to avoid N+1 query problems.

Mitigating potential pitfalls

Be mindful and wary of these potential bumps you may encounter:

Over-reliance on select_related may lead to heavier and slower SQL queries. Use with discretion.
Incorrect chaining of attributes can trigger AttributeErrors – programmers’ greatest fear. Double-check the chains.
Overburdening your list_display without optimizing queries can result in painfully slow admin load times – your test users will thank you for paying attention to this.

Tuning admin interface for pleasant user experience

Custom column headers

Your users will be happier with well-sorted and neatly labeled data columns. It's as simple as adjusting the short_description property:

author_name.short_description = 'Author Full Name'  # "Full name", it's a formal affair…!

Multipurpose callable methods

Feeling frisky? Throw in some concatenated values or apply custom formatting straight in a callable:

def author_and_book(self, obj):
    # 'concatenate' is a long word, but gives concise results! 🤓
    return '{} -
            {}'.format(obj.author.name, obj.title)
author_and_book.short_description = 'Author & Book'