How to change ForeignKey display text in the Django Admin?

Question

How can I change the display text in a <select> field while selecting a field which is a ForeignKey?

I need to display not only the name of ForeignKey, but also the name of it's parent.

Answer 1

If you want it to take effect only in admin, and not globally, then you could create a custom ModelChoiceField subclass, use that in a custom ModelForm and then set the relevant admin class to use your customized form. Using an example which has a ForeignKey to the Person model used by @Enrique:

class Invoice(models.Model):
      person = models.ForeignKey(Person)
      ....

class InvoiceAdmin(admin.ModelAdmin):
      form = MyInvoiceAdminForm


class MyInvoiceAdminForm(forms.ModelForm):
    person = CustomModelChoiceField(queryset=Person.objects.all()) 
    class Meta:
          model = Invoice
      
class CustomModelChoiceField(forms.ModelChoiceField):
     def label_from_instance(self, obj):
         return "%s %s" % (obj.first_name, obj.last_name)