Refs #23820.
Fixed#19738.
Refs #17755. In order not to introduce a regression for raw queries,
parameters are passed through the connection.ops.value_to_db_* methods,
depending on their type.
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.
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.
Refs #23073 Workaround.
Refs #22738 Repeats the mysql "offense". When the issue is solved, the
Oracle special case should be made to play with the solution (that is,
Oracle should be fixed the same way that mysql and the 3rd-party backneds
are).
This is achieved by inserting a fake entry in connection.queries when
not releasing a savepoint (since Oracle doesn't support that operation.)
Also removed the can_release_savepoints feature that was recently added,
but is superseded by this solution.
This seems worthwhile in its own right, but also works around an Oracle
bug (in versions 10 -- 11.1) where the use of Unicode would reset the
date/time formats, causing ORA-01843 errors.
Thanks Trac users CarstenF for the report, jtiai for the initial patch,
and everyone who contributed to the discussion on the ticket.
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()'.
Also ensured the transaction state is clean on Oracle while I was there.
This change cannot be backported to 1.6 because it's
backwards-incompatible for custom database backends.
Maxime Lorant
Tim Graham
Aymeric Augustin
Anssi Kääriäinen
Marc Tamlyn
Shai Berger
Josh Smeaton
Jon Dufresne
Thomas Chaumeny
Claude Paroz
Anubhav Joshi
Aymeric Augustin
Alex Gaynor
Simon Charette
Rodolfo Carvalho
Andrew Godwin
Michael Manfre
Levi Gross
Loic Bistuer