[FIXED] How to change ForeignKey display text in the Django Admin?

Issue

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 its parent.

Solution

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)

Answered By - Botond Béres