Commit 88c17b58 authored by Malcolm Tredinnick's avatar Malcolm Tredinnick
Browse files

Documented that the update() method on querysets is a direct SQL call, not the 

same as looping over the queryset and calling save() on each item (which is
less efficient). Fixed #7447.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@7884 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent 7936c0b9

docs/db-api.txt

+12 −0
Original line number Diff line number Diff line
@@ -2212,6 +2212,18 @@ updated is that it can only access one database table, the model's main 
table. So don't try to filter based on related fields or anything like that;

it won't work.



Be aware that the ``update()`` method is converted directly to an SQL

statement. It is a bulk operation for direct updates. It doesn't run any

``save()`` methods on your models, or emit the ``pre_save`` or ``post_save``

signals (which are a consequence of calling ``save()``). If you want to save

every item in a ``QuerySet`` and make sure that the ``save()`` method is

called on each instance, you don't need any special function to handle that.

Just loop over them and call ``save()``:



    for item in my_queryset:

        item.save()





Extra instance methods

======================