Django equivalent of SQL REPLACE

You say you want REPLACE, which I believe is supposed to delete any existing rows before inserting, but your example indicates you want something more like UPSERT.

AFAIK, django doesn't support REPLACE (or sqlite's INSERT OR REPLACE, or UPSERT). But your code could be consolidated:

obj, created = Model.objects.get_or_create(field_1='some val', field_2='some_val')
obj.extra_field = 'some_val'
obj.save()

This of course assumes that either field_1, field_2, or both are unique (as you've said).

It's still two queries (a SELECT for get_or_create, and an INSERT or UPDATE for save), but until an UPSERT-like solution comes along (and it may not for a long, long time), it may be the best you can do.

Since Django 1.7 you can use update_or_create method:

obj, created = Person.objects.update_or_create(
    first_name='John',
    last_name='Lennon',
    defaults={'profession': 'musician'},
)

I think the following is more efficient.

(obj, created) = Model.objects.get_or_create(
   field_1 = 'some val',
   field_2 = 'some_val',
   defaults = {
      'extra_field': 'some_val'
   },
)
if not created and obj.extra_field != 'some_val':
   obj.extra_field = 'some_val'
   obj.save(
      update_fields = [
         'extra_field',
      ],
   )

This will only update the extra_field if the row was not created and needs to be updated.