Refs #28333 -- Added partial support for filtering against window functions.

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.

1 files changed, 7 insertions, 4 deletions

diff --git a/django/db/backends/mysql/compiler.py b/django/db/backends/mysql/compiler.py
index a8ab03a55e..bd2715fb43 100644
--- a/django/db/backends/mysql/compiler.py
+++ b/django/db/backends/mysql/compiler.py
@@ -28,10 +28,13 @@ class SQLDeleteCompiler(compiler.SQLDeleteCompiler, SQLCompiler):
         # the SQLDeleteCompiler's default implementation when multiple tables
         # are involved since MySQL/MariaDB will generate a more efficient query
         # plan than when using a subquery.
-        where, having = self.query.where.split_having()
-        if self.single_alias or having:
-            # DELETE FROM cannot be used when filtering against aggregates
-            # since it doesn't allow for GROUP BY and HAVING clauses.
+        where, having, qualify = self.query.where.split_having_qualify(
+            must_group_by=self.query.group_by is not None
+        )
+        if self.single_alias or having or qualify:
+            # DELETE FROM cannot be used when filtering against aggregates or
+            # window functions as it doesn't allow for GROUP BY/HAVING clauses
+            # and the subquery wrapping (necessary to emulate QUALIFY).
             return super().as_sql()
         result = [
             "DELETE %s FROM"