F() expressions reuse joins like any lookup in a .filter() call -
reuse multijoins generated in the same .filter() call else generate
new joins. Also, lookups can now reuse joins generated by F().
This change is backwards incompatible, but it is required to prevent
dict randomization from generating different queries depending on
.filter() kwarg ordering. The new way is also more consistent in how
joins are reused.
The dupe avoidance logic was removed as it doesn't seem to do anything,
it is complicated, and it has nearly zero documentation.
The removal of dupe_avoidance allowed for refactoring of both the
implementation and signature of Query.join(). This refactoring cascades
again to some other parts. The most significant of them is the changes
in qs.combine(), and compiler.select_related_descent().
The Query.select and Query.select_fields were collapsed into one list
because the attributes had to be always in sync. Now that they are in
one attribute it is impossible to edit them out of sync.
Similar collapse was done for Query.related_select_cols and
Query.related_select_fields.
There was a bug introduced in #18676 which caused fast-path deletes
implemented as "DELETE WHERE pk IN <subquery>" to fail if the SELECT
clause contained additional stuff (for example extra() and annotate()).
Thanks to Trac alias pressureman for spotting this regression.
In an ideal world, nothing except django.db.models.query should have to
import stuff from django.models.sql.*. A few things were needing to get
hold of sql.constants.LOOKUP_SEP, so this commit moves it up to
django.db.models.constants.LOOKUP_SEP.
There are still a couple of places (admin) poking into sql.* to get
QUERY_TERMS, which is unfortunate, but a slightly different issue and
harder to adjust.
The joins for nested nullable foreign keys were often created as INNER
when they should have been OUTER joins. The reason was that only the
first join in the chain was promoted correctly. There were also issues
with select_related etc.
The basic structure for this problem was:
A -[nullable]-> B -[nonnull]-> C
And the basic problem was that the A->B join was correctly LOUTER,
the B->C join not.
The major change taken in this patch is that now if we promote a join
A->B, we will automatically promote joins B->X for all X in the query.
Also, we now make sure there aren't ever join chains like:
a LOUTER b INNER c
If the a -> b needs to be LOUTER, then the INNER at the end of the
chain will cancel the LOUTER join and we have a broken query.
Sebastian reported this problem and did also major portions of the
patch.
The ORM generated a query with INNER JOIN instead of LEFT OUTER JOIN
in a somewhat complicated case. The main issue was that there was a
chain of nullable FK -> non-nullble FK, and the join promotion logic
didn't see the need to promote the non-nullable FK even if the
previous nullable FK was already promoted to LOUTER JOIN. This resulted
in a query like a LOUTER b INNER c, which incorrectly prunes results.
* 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.
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.
Fixed#18248 -- proxy models were added to included_inherited_models
in sql.query.Query. The variable is meant to be used for multitable
inheritance only. This mistake caused problems in situations where
proxy model's query was reused.
Fixed#17957 -- when using Oracle and character fields, the fields
were set null = True to ease the handling of empty strings. This
caused problems when using multiple databases from different vendors,
or when the character field happened to be also a primary key.
The handling was changed so that NOT NULL is not emitted on Oracle
even if field.null = False, and field.null is not touched otherwise.
Thanks to bhuztez for the report, ramiro for triaging & comments,
ikelly for the patch and alex for reviewing.
QuerySet had previously some complex logic for dealing with nullable
fields in negated add_filter() calls. It seems the logic is leftover
from a time where the WhereNode wasn't as intelligent in handling
field__in=[] conditions.
Thanks to aaugustin for comments on the patch.
only consider some fields (PostgreSQL only).
For this, the ``distinct()`` QuerySet method now accepts an optional
list of model fields names and generates ``DISTINCT ON`` clauses on
these cases. Thanks Jeffrey Gelens and Anssi Kääriäinen for their work.
Fixes#6422.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@17244 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This is the old Query.as_sql() method revived: it's like Query.__str__,
but the parameters aren't substituted into the placeholders. Thus, it's
a more accurate representation of the SQL the (default) backend will
see. Entirely internal.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@16655 bcc190cf-cafb-0310-a4f2-bffc1f526a37
A number of people worked on this patch over the years -- Hawkeye, Colin Grady,
KBS, sakyamuni, anih, jdemoor, and Issak Kelly. Thanks to them all, and
apologies if I missed anyone.
Special thanks to Dan Fairs for picking it up again at the end and seeing this
through to commit.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@16058 bcc190cf-cafb-0310-a4f2-bffc1f526a37
Turns out that a lot more than just SELECT can return data, and this list is
very hard to define up front in a cross-database manner. So let's just assume
that anyone using raw() is at least halfway competant and can deal with
the error messages if they don't use a data-returning query.
Thanks to Christophe Pettus for the patch.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@15803 bcc190cf-cafb-0310-a4f2-bffc1f526a37
as that can lead to incorrect SQL being generated for the query. Thanks to mat
for the report and test, tobias for the fix, and Alex for review.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@12830 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This monster of a patch is the result of Alex Gaynor's 2009 Google Summer of Code project.
Congratulations to Alex for a job well done.
Big thanks also go to:
* Justin Bronn for keeping GIS in line with the changes,
* Karen Tracey and Jani Tiainen for their help testing Oracle support
* Brett Hoerner, Jon Loyens, and Craig Kimmerer for their feedback.
* Malcolm Treddinick for his guidance during the GSoC submission process.
* Simon Willison for driving the original design process
* Cal Henderson for complaining about ponies he wanted.
... and everyone else too numerous to mention that helped to bring this feature into fruition.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@11952 bcc190cf-cafb-0310-a4f2-bffc1f526a37
See `docs/topics/db/raw.txt` for details.
Thanks to seanoc for getting the ball rolling, and to Russ for wrapping things up.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@11921 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This enables querysets with an extra clause to be used in an __in filter; as a side effect, it also means that as_sql() now returns the correct result for any query with an extra clause.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@10648 bcc190cf-cafb-0310-a4f2-bffc1f526a37
Using select_related(...) across a nullable relation to a multi-table
model inheritance situation no longer excludes results. Thanks to AdamG
for a test demonstrating part of the problem.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@10136 bcc190cf-cafb-0310-a4f2-bffc1f526a37
In extreme cases, some fields are expensive to load from the database
(e.g. GIS fields requiring conversion, or large text fields). This
commit adds defer() and only() methods to querysets that allow the
caller to specify which fields should not be loaded unless they are
accessed.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@10090 bcc190cf-cafb-0310-a4f2-bffc1f526a37
Large portions of this are needed for #5420, so I implemented it fully.
Thanks to Ryan Kelly for an initial patch to get this started.
Refs #5420.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@10083 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This fixes a broad class of bugs involving filters that look for missing
related models and fields. Most of them don't seem to have been reported
(the added tests cover the root cause). The exception is that this has
also fixed#9868.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@9979 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This includes a fairly large refactor of the update() query path (and
the initial portions of constructing the SQL for any query). The
previous code appears to have been only working more or less by accident
and was very fragile.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@9967 bcc190cf-cafb-0310-a4f2-bffc1f526a37
Some results were inadvertently being excluded if we were ordering across a
nullable relation which itself ordering by a non-nullable relation.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@9916 bcc190cf-cafb-0310-a4f2-bffc1f526a37
Anssi Kääriäinen
Malcolm Tredinnick
Alex Gaynor
Alex Gaynor
Aymeric Augustin
Claude Paroz
Adrian Holovaty
Carl Meyer
Julien Phalip
Ramiro Morales
Karen Tracey
Russell Keith-Magee
Jannis Leidel
Luke Plant
Jacob Kaplan-Moss
Justin Bronn
Ian Kelly
Gary Wilson Jr