db.models.query.QuerySet.update_or_create()

update_or_create(defaults=None, **kwargs)

A convenience method for updating an object with the given kwargs, creating a new one if necessary. The defaults is a dictionary of (field, value) pairs used to update the object.

Returns a tuple of (object, created), where object is the created or updated object and created is a boolean specifying whether a new object was created.

The update_or_create method tries to fetch an object from database based on the given kwargs. If a match is found, it updates the fields passed in the defaults dictionary.

This is meant as a shortcut to boilerplatish code. For example:

try:
    obj = Person.objects.get(first_name='John', last_name='Lennon')
    for key, value in updated_values.iteritems():
        setattr(obj, key, value)
    obj.save()
except Person.DoesNotExist:
    updated_values.update({'first_name': 'John', 'last_name': 'Lennon'})
    obj = Person(**updated_values)
    obj.save()

This pattern gets quite unwieldy as the number of fields in a model goes up. The above example can be rewritten using update_or_create() like so:

obj, created = Person.objects.update_or_create(
    first_name='John', last_name='Lennon', defaults=updated_values)

For detailed description how names passed in kwargs are resolved see get_or_create().

As described above in get_or_create(), this method is prone to a race-condition which can result in multiple rows being inserted simultaneously if uniqueness is not enforced at the database level.