This should allow smarter output_field inferring in functions dealing
with text expressions.
Regression in f333e3513e.
Backport of 8b1acc0440 from main
Special thanks to Hannes Ljungberg for finding multiple implementation
gaps.
Thanks also to Simon Charette, Adam Johnson, and Mariusz Felisiak for
reviews.
Black 23.1.0 is released which, as the first release of the year,
introduces the 2023 stable style. This incorporates most of last year's
preview style.
https://github.com/psf/black/releases/tag/23.1.0
Adjusting WhereNode.as_sql() to raise an exception when encoutering a
full match just like with empty matches ensures that all case are
explicitly handled.
This required moving the combined queries slicing logic to the compiler
in order to allow Query.exists() to be called at expression resolving
time.
It allowed for Query.exists() to be called at Exists() initialization
time and thus ensured that get_group_by_cols() was operating on the
terminal representation of the query that only has a single column
selected.
This ensures explicit grouping from using values() before annotating an
aggregate function groups by selected aliases if supported.
The GROUP BY feature is disabled on Oracle because it doesn't support it.
A more in-depth solution is likely to make sure that we always GROUP BY
selected annotations or revisit how we use Query.exists() in the Exists
expression but that requires extra work that isn't suitable for a
backport.
Regression in e5a92d400a.
Thanks Fernando Flores Villaça for the report.
Adds support for joint predicates against window annotations through
subquery wrapping while maintaining errors for disjointed filter
attempts.
The "qualify" wording was used to refer to predicates against window
annotations as it's the name of a specialized Snowflake extension to
SQL that is to window functions what HAVING is to aggregates.
While not complete the implementation should cover most of the common
use cases for filtering against window functions without requiring
the complex subquery pushdown and predicate re-aliasing machinery to
deal with disjointed predicates against columns, aggregates, and window
functions.
A complete disjointed filtering implementation should likely be
deferred until proper QUALIFY support lands or the ORM gains a proper
subquery pushdown interface.
This includes refactoring of CombinedExpression._resolve_output_field()
so it no longer uses the behavior inherited from Expression of guessing
same output type if argument types match, and instead we explicitly
define the output type of all supported operations.
This also makes nonsensical operations involving dates
(e.g. date + date) raise a FieldError, and adds support for
automatically inferring output_field for cases such as:
* date - date
* date + duration
* date - duration
* time + duration
* time - time
As a QuerySet resolves to Query the outer column references grouping logic
should be defined on the latter and proxied from Subquery for the cases where
get_group_by_cols is called on unresolved expressions.
Thanks Antonio Terceiro for the report and initial patch.
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.
