As suggested by Anssi. This has the slightly strange side effect of
passing the expression to Expression.convert_value has the expression
passed back to it, but it allows more complex patterns of expressions.
The method is mainly intended for use with UUIDField. For UUIDField we
want to call the field's default even when primary key value is
explicitly set to None to match the behavior of AutoField.
Thanks to Marc Tamlyn and Tim Graham for review.
Refactored compiler SELECT, GROUP BY and ORDER BY generation.
While there, also refactored select_related() implementation
(get_cached_row() and get_klass_info() are now gone!).
Made get_db_converters() method work on expressions instead of
internal_type. This allows the backend converters to target
specific expressions if need be.
Added query.context, this can be used to set per-query state.
Also changed the signature of database converters. They now accept
context as an argument.
Added functions and tests
Added docs and more tests
Added TextField converter to mysql backend
Aliased Value as V in example docs and tests
Removed unicode_compatible in example
Fixed console emulation in examples
Use INTERVAL DAY(9) TO SECOND(6) for Durationfield on Oracle rather than
storing as a NUMBER(19) of microseconds.
There are issues with cx_Oracle which require some extra data
manipulation in the database backend when constructing queries, but it
handles the conversion back to timedelta objects cleanly.
Thanks to Shai for the review.
A field for storing periods of time - modeled in Python by timedelta. It
is stored in the native interval data type on PostgreSQL and as a bigint
of microseconds on other backends.
Also includes significant changes to the internals of time related maths
in expressions, including the removal of DateModifierNode.
Thanks to Tim and Josh in particular for reviews.
Complete rework of translating data values from database
Deprecation of SubfieldBase, removal of resolve_columns and
convert_values in favour of a more general converter based approach and
public API Field.from_db_value(). Now works seamlessly with aggregation,
.values() and raw queries.
Thanks to akaariai in particular for extensive advice and inspiration,
also to shaib, manfre and timograham for their reviews.
The Model.from_db() is intended to be used in cases where customization
of model loading is needed. Reasons can be performance, or adding custom
behavior to the model (for example "dirty field tracking" to issue
automatic update_fields when saving models).
A big thank you to Tim Graham for the review!
Added DateTimeCheckMixin to avoid the use of default, auto_now, and
auto_now_add options together. Added the fields.E151 Error that is raised
if one or more of these options are used together.
The ticket was originally about two failing tests, which are
fixed by putting their queries in transactions.
Thanks Tim Graham for the report, Aymeric Augustin for the fix,
and Simon Charette, Tim Graham & Loïc Bistuer for review.
The original patch for custom prefetches didn't allow usage of custom
queryset for single valued relations (along ForeignKey or OneToOneKey).
Allowing these enables calling performance oriented queryset methods like
select_related or defer/only.
Thanks @akaariai and @timgraham for the reviews. Refs #17001.
Previously, doing so resulted in invalid data or crash.
Thanks jtiai for the report and Karol Jochelson,
Jakub Nowak, Loic Bistuer, and Baptiste Mispelon for reviews.
ForeignKey or ManyToManyField attribute ``limit_choices_to`` can now
be a callable that returns either a ``Q`` object or a dict.
Thanks michael at actrix.gen.nz for the original suggestion.
Overriding the error messages now works for both unique fields, unique_together
and unique_for_date.
This patch changed the overriding logic to allow customizing NON_FIELD_ERRORS
since previously only fields' errors were customizable.
Refs #20199.
Thanks leahculver for the suggestion.
Allowed users to specify which lookups or transforms ("nested lookus")
are available for fields. The implementation is now class based.
Squashed commit of the following:
commit fa7a7195f1
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Jan 18 10:53:24 2014 +0200
Added lookup registration API docs
commit eb1c8ce164
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Tue Jan 14 18:59:36 2014 +0200
Release notes and other minor docs changes
commit 11501c29c9
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sun Jan 12 20:53:03 2014 +0200
Forgot to add custom_lookups tests in prev commit
commit 83173b960e
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sun Jan 12 19:59:12 2014 +0200
Renamed Extract -> Transform
commit 3b18d9f3a1
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sun Jan 12 19:51:53 2014 +0200
Removed suggestion of temporary lookup registration from docs
commit 21d0c7631c
Merge: 2509006f2dc442
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sun Jan 12 09:38:23 2014 -0800
Merge pull request #2 from mjtamlyn/lookups_3
Reworked custom lookups docs.
commit f2dc4429a1
Author: Marc Tamlyn <marc.tamlyn@gmail.com>
Date: Sun Jan 12 13:15:05 2014 +0000
Reworked custom lookups docs.
Mostly just formatting and rewording, but also replaced the example
using ``YearExtract`` to use an example which is unlikely to ever be
possible directly in the ORM.
commit 2509006506
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sun Jan 12 13:19:13 2014 +0200
Removed unused import
commit 4fba5dfaa0
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Jan 11 22:34:41 2014 +0200
Added docs to index
commit 6d53963f37
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Jan 11 22:10:24 2014 +0200
Dead code removal
commit f9cc039007
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Jan 11 19:00:43 2014 +0200
A new try for docs
commit 33aa18a6e3
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Jan 11 14:57:12 2014 +0200
Renamed get_cols to get_group_by_cols
commit c7d5f8661b
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Jan 11 14:45:53 2014 +0200
Altered query string customization for backends vendors
The new way is trying to call first method 'as_' + connection.vendor.
If that doesn't exist, then call as_sql().
Also altered how lookup registration is done. There is now
RegisterLookupMixin class that is used by Field, Extract and
sql.Aggregate. This allows one to register lookups for extracts and
aggregates in the same way lookup registration is done for fields.
commit 90e7004ec1
Merge: 66649fff7c2c0a
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Jan 11 13:21:01 2014 +0200
Merge branch 'master' into lookups_3
commit 66649ff891
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Jan 11 13:16:01 2014 +0200
Some rewording in docs
commit 31b8faa627
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sun Dec 29 15:52:29 2013 +0200
Cleanup based on review comments
commit 1016159f34
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Dec 28 18:37:04 2013 +0200
Proof-of-concept fix for #16731
Implemented only for SQLite and PostgreSQL, and only for startswith
and istartswith lookups.
commit 193cd097ca
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Dec 28 17:57:58 2013 +0200
Fixed#11722 -- iexact=F() produced invalid SQL
commit 08ed3c3b49
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Dec 21 23:59:52 2013 +0200
Made Lookup and Extract available from django.db.models
commit b99c8d83c9
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Dec 21 23:06:29 2013 +0200
Fixed review notes by Loic
commit 049eebc070
Merge: ed8fab7b80a835
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Dec 21 22:53:10 2013 +0200
Merge branch 'master' into lookups_3
Conflicts:
django/db/models/fields/__init__.py
django/db/models/sql/compiler.py
django/db/models/sql/query.py
tests/null_queries/tests.py
commit ed8fab7fe8
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Dec 21 22:47:23 2013 +0200
Made Extracts aware of full lookup path
commit 27a57b7aed
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sun Dec 1 21:10:11 2013 +0200
Removed debugger import
commit 074e0f5aca
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sun Dec 1 21:02:16 2013 +0200
GIS lookup support added
commit 760e28e72b
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sun Dec 1 20:04:31 2013 +0200
Removed usage of Constraint, used Lookup instead
commit eac4776684
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sun Dec 1 02:22:30 2013 +0200
Minor cleanup of Lookup API
commit 2adf50428d
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sun Dec 1 02:14:19 2013 +0200
Added documentation, polished implementation
commit 32c04357a8
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Nov 30 23:10:15 2013 +0200
Avoid OrderedDict creation on lookup aggregate check
commit 7c8b3a32cc
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Sat Nov 30 23:04:34 2013 +0200
Implemented nested lookups
But there is no support of using lookups outside filtering yet.
commit 4d219d4cde
Author: Anssi Kääriäinen <akaariai@gmail.com>
Date: Wed Nov 27 22:07:30 2013 +0200
Initial implementation of custom lookups
Using callables as query parameters is undocumented and not working,
so this changes an example from the ForeignKey.limit_choices_to
documentation that uses it.
The `remove()` and `clear()` methods of the related managers created by
`ForeignKey`, `GenericForeignKey`, and `ManyToManyField` suffered from a
number of issues. Some operations ran multiple data modifying queries without
wrapping them in a transaction, and some operations didn't respect default
filtering when it was present (i.e. when the default manager on the related
model implemented a custom `get_queryset()`).
Fixing the issues introduced some backward incompatible changes:
- The implementation of `remove()` for `ForeignKey` related managers changed
from a series of `Model.save()` calls to a single `QuerySet.update()` call.
The change means that `pre_save` and `post_save` signals aren't called anymore.
- The `remove()` and `clear()` methods for `GenericForeignKey` related
managers now perform bulk delete so `Model.delete()` isn't called anymore.
- The `remove()` and `clear()` methods for `ManyToManyField` related
managers perform nested queries when filtering is involved, which may
or may not be an issue depending on the database and the data itself.
Refs. #3871, #21174.
Thanks Anssi Kääriäinen and Tim Graham for the reviews.
The issue was that two M2M hidden reverse managers
(related_name ending with a '+') could clash with each other.
Refs #21375 and #15932. Thanks Baptiste.
Added an explicit mention of the exact value ranges for integer type
fields that are safe in all databases supported by Django. Also, put
all value numbers inside double ticks.
This patch introduces the Prefetch object which allows customizing prefetch
operations.
This enables things like filtering prefetched relations, calling select_related
from a prefetched relation, or prefetching the same relation multiple times
with different querysets.
When a Prefetch instance specifies a to_attr argument, the result is stored
in a list rather than a QuerySet. This has the fortunate consequence of being
significantly faster. The preformance improvement is due to the fact that we
save the costly creation of a QuerySet instance.
Thanks @akaariai for the original patch and @bmispelon and @timgraham
for the reviews.
Thanks dan at dlo.me for the initial patch.
- Added __pow__ and __rpow__ to ExpressionNode
- Added oracle and mysql specific power expressions
- Added used-defined power function for sqlite
select_related('foo').select_related('bar') is now equivalent to
select_related('foo', 'bar').
Also reworded docs to recommend select_related(*fields) over select_related()
The option can be used to force pre 1.6 style SELECT on save behaviour.
This is needed in case the database returns zero updated rows even if
there is a matching row in the DB. One such case is PostgreSQL update
trigger that returns NULL.
Reviewed by Tim Graham.
Refs #16649
The __eq__ method now considers two instances without primary key value
equal only when they have same id(). The __hash__ method raises
TypeError for no primary key case.
Fixed#18864, fixed#18250
Thanks to Tim Graham for docs review.
Added OneToOneField to the list of model fields for which the unique
argument isn't valid. (OneToOneFields are inherently unique, and if
the user supplies a value for unique it is ignored / overwritten.)
