Models that use SET, SET_NULL, and SET_DEFAULT as on_delete handler
don't have to fetch objects for the sole purpose of passing them back to
a follow up UPDATE query filtered by the retrieved objects primary key.
This was achieved by flagging SET handlers as _lazy_ and having the
collector logic defer object collections until the last minute. This
should ensure that the rare cases where custom on_delete handlers are
defined remain uncalled when when dealing with an empty collection of
instances.
This reduces the number queries required to apply SET handlers from
2 to 1 where the remaining UPDATE use the same predicate as the non
removed SELECT query.
In a lot of ways this is similar to the fast-delete optimization that
was added in #18676 but for updates this time. The conditions only
happen to be simpler in this case because SET handlers are always
terminal. They never cascade to more deletes that can be combined.
Thanks Renan GEHAN for the report.
This has been supported for subqueries wrapped in Subquery since the expression
was introduced and for Queryset directly since Subquery resolves to sql.Query.
Piggy-backed on the existing tests covering Coalesce handling of EmptyResultSet
as it seemed like a proper location to combine testing.
Selected rows where not highlighted when returning to the change-list
after clicking "No, take me back" on the deletion confirmation page.
This commit uses the CSS :has() pseudo-class to apply the highlight
without requiring the .selected class, which is added by JavaScript
on the click event.
Once all supported browsers have :has() available, the .selected
selector and the JavaScript to add the class can be removed.
Co-authored-by: Carlton Gibson <carlton.gibson@noumenal.es>
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.
Allen Jonathan David
Shai Berger
Mariusz Felisiak
Alex Morega
Swara
Simon Charette
Iván Camilo Triviño López
Ilia Peterov
Mohamed Karam
David Wobrock
Iuri de Silvio
Jan Pieter Waagmeester
Neeraj Kumar
Daniel Hahler
Willem Van Onsem
Kanza
Claude Paroz
Tom Carrick
Jacob Rief
Benoît Vinot
Carlton Gibson
Marcelo Galigniana
Youssef
Haolun Chai
Mohammadtaher Abbasi