Django: how can I update more than one record at once?
If you have to update each record with a different value, then of couse you have to iterate over each record. If you wish to do update them all with the same value, then just use the update method of the queryset.
How can I update multiple records in a queryset efficiently? 
Do I just loop over the queryset, edit , and call save() for each one of them? Is it equivalent to psycopg2's executemany?