Deferred models now automatically update only the fields which are
loaded from the db (with .only() or .defer()). In addition, any field
set manually after the load is updated on save.
* Renamed the __unicode__ methods
* Applied the python_2_unicode_compatible decorator
* Removed the StrAndUnicode mix-in that is superseded by
python_2_unicode_compatible
* Kept the __unicode__ methods in classes that specifically
test it under Python 2
* Renamed smart_unicode to smart_text (but kept the old name under
Python 2 for backwards compatibility).
* Renamed smart_str to smart_bytes.
* Re-introduced smart_str as an alias for smart_text under Python 3
and smart_bytes under Python 2 (which is backwards compatible).
Thus smart_str always returns a str objects.
* Used the new smart_str in a few places where both Python 2 and 3
want a str.
cleaned_data is no longer deleted when form validation fails but only
contains the data that did validate.
Thanks to the various contributors to this patch (see ticket).
Cleared aggregations on add_date_select method so only distinct dates
are returned when dealing with a QuerySet that contained aggregations.
That would cause the query set to return repeated dates because it
would look for distinct (date kind, aggregation) pairs.
This commit tackles a couple of issues. First, in certain cases there
were some mixups if field.attname or field.name should be deferred.
Field.attname is now always used.
Another issue tackled is a case where field is both deferred by
.only(), and selected by select_related. This case is now an error.
A lot of thanks to koniiiik (Michal Petrucha) for the patch, and
to Andrei Antoukh for review.
Generic cleanup and dead code removal in deferred model field loading
and model.__reduce__().
Also fixed an issue where if an inherited model with a parent field
chain parent_ptr_id -> id would be deferred loaded, then accessing
the id field caused caused a database query, even if the id field's
value is already loaded in the parent_ptr_id field.
This was recently fixed for one-to-one relations; this patch adds
support for foreign keys. Thanks kaiser.yann for the report and
the initial version of the patch.
Databases with update_can_self_select = False (MySQL for example)
generated non-necessary queries when saving a multitable inherited
model, and when the save resulted in update.
MySQL generates an extra query in inheritance cases when doing an update.
This results in a test failure when checking for number of queries in
update_only_fields tests. Added a skip temporarily to avoid this test
failure. Refs #18304.
Added the ability to update only part of the model's fields in
model.save() by introducing a new kwarg "update_fields". Thanks
to all the numerous reviewers and commenters in the ticket
Aymeric Augustin
Andrei Antoukh
Karen Tracey
Claude Paroz
Alex Gaynor
Anssi Kääriäinen
Nuno Maltez
Luke Plant
Honza Kral
Simon Charette