Django: check whether an object already exists before adding

Question

This is a pretty simple Django question, but I can\'t find the answer in the Django docs, despite lots of hunting!

How do I check whether an object already exists, and o

Answer 1

If you want the check done every time before save you could use the pre save signal to check, http://docs.djangoproject.com/en/dev/ref/signals/#django.db.models.signals.pre_save

Alternatively in the model you could specify unique=True for the property that determines whether an item is the same item, this will cause an Exception (django.db.IntegrityError) to be thrown if you try to save the same thing again.

If you have more than one field together that makes something unique you'll need to use unique_together in the Meta inner class http://docs.djangoproject.com/en/dev/ref/models/options/#unique-together