When the query's model had a self-referential foreign key, the
compiler.get_group_by() code incorrectly used the self-referential
foreign key's column (for example parent_id) as GROUP BY clause
when it should have used the model's primary key column (id).
Fixed queries where an expression was used in order_by() but the
expression wasn't in the query's select clause (for example the
expression could be masked by .values() call)
Thanks to Trac alias MattBlack85 for the report.
Field.rel is now deprecated. Rel objects have now also remote_field
attribute. This means that self == self.remote_field.remote_field.
In addition, made the Rel objects a bit more like Field objects. Still,
marked ManyToManyFields as null=True.
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.
Instead of splitting filter clauses to where and having parts before
adding them to query.where or query.having, add all filter clauses to
query.where, and when compiling the query split the where to having and
where parts.
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.
Also removed Query.join_map. This structure was used to speed up join
reuse calculation. Initial benchmarking shows that this isn't actually
needed. If there are use cases where the removal has real-world
performance implications, it should be relatively straightforward to
reintroduce it as map {alias: [Join-like objects]}.
Aggregation over subquery produced syntactically incorrect queries in
some cases as Django didn't ensure that source expressions of the
aggregation were present in the subquery.
The .dates() queries were implemented by using custom Query, QuerySet,
and Compiler classes. Instead implement them by using expressions and
database converters APIs.
Added relabeled_clone() method to sql.Query to fix the problem. It
manifested itself in rare cases where at least double nested subquery's
filter condition might target non-existing alias.
Thanks to Trac alias ris for reporting the problem.
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.
A regression caused queries to produce incorrect results for cases where
extra(select) is excluded by values() but included by extra(order_by)
The regression was caused by 2f35c6f10f.
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.
Previously, saving a model instance to a non-related field (in
particular a FloatField) would silently convert the model to an Integer
(the pk) and save it. This is undesirable behaviour, and likely to cause
confusion so the validatio has been hardened.
Thanks to @PirosB3 for the patch and @jarshwah for the review.
This commit touchs various parts of the code base and test framework. Any
found usage of opening a cursor for the sake of initializing a connection
has been replaced with 'ensure_connection()'.
Tim Graham
Alex Hill
Valentina Mukhamedzhanova
risicle
Anssi Kääriäinen
Simon Charette
Anssi Kääriäinen
Jay Wineinger
Marc Tamlyn
Claude Paroz
Josh Smeaton
Michał Modzelewski
Daniel Pyrathon
Niclas Olofsson
Carl Meyer
Rajiv Makhijani
Anubhav Joshi
Jorge C. Leitão
Alex Gaynor
Shai Berger
Rodolfo Carvalho
Michael Manfre