Of the built-in backends, only Oracle treats empty strings and nulls as
equal, so avoid testing the default connection backend for
interprets_empty_strings_as_nulls if it can be established from the
lookup that it wouldn't affect the lookup instance returned. This
improves performance a small amount for most lookups being built,
because accessing the connections requires touching the thread critical
`Local` which is an expensive operation.
The functionality of updating the __dict__ was only present to allow
for pickling a Prefetch object, which is a comparably rare operation.
Forcing the __getstate__() implementation to handle it allows the
chaining operation to be slightly faster, which is much more common.
Since ManyToManyFields defined with `symmetrical=True` do not add a
related field to the target model, including a `related_name` argument
will never do what the coder likely expects. This makes including
a related_name with a symmetrical model raise a system check warning.
ticket-32983
This prefers non-kwargs construction of dynamically generated Q()
objects to create a single Q() object instead of many and then
combining them, where possible.
This also removes unnecessary comments with the previous spelling.
AP Stylebook has a short entry to advise the preferred spelling for
"en-us". "Afterwards" is preferred in British English.
The Python's Steering Council decided to revert changes in the Enum
module (see https://bugs.python.org/issue44559) and moved them to
Python 3.11.
Follow up to 5d9b065d3f.
Thanks Nick Pope for the review.
get_col() used "self" as "output_field" when it was not given, and
unnecessarily compared "self" to "self".
Co-authored-by: Chris Jerdonek <chris.jerdonek@gmail.com>
Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>
This is useful when working with database routing as you want to know
where each query is being executed.
Co-authored-by: David Winterbottom <david.winterbottom@gmail.com>
The introduction of the Expression.empty_aggregate_value interface
allows the compilation stage to enable the EmptyResultSet optimization
if all the aggregates expressions implement it.
This also removes unnecessary RegrCount/Count.convert_value() methods.
Disabling the empty result set aggregation optimization when it wasn't
appropriate prevented None returned for a Count aggregation value.
Thanks Nick Pope for the review.
Migrations assumed that an import of the models.Model class must
already be included when it's serialized, but for models with only
custom fields this was not necessarily the case.
Thanks Jaap Joris Vens for the report.
Hasan Ramezani
David Wobrock
Mariusz Felisiak
Jacob Walls
Mateo Radman
Manav Agarwal
Tim Graham
Matjaz Gregoric
Keryn Knight
Chris Jerdonek
Nick Touran
David Smith
Jordan Bae
Tom Wojcik
Nick Pope
Daniyal
Ian Foote
Wu Haotian
Simon Charette
abhiabhi94
Hannes Ljungberg