Address a long standing bug in a Where.add optimization to discard
equal nodes that was surfaced by implementing equality for Lookup
instances in bbf141bcdc31f1324048af9233583a523ac54c94.
Thanks Shaheed Haque for the report.
Subquery deconstruction support required implementing complex and
expensive equality rules for sql.Query objects for little benefit as
the latter cannot themselves be made deconstructible to their reference
to model classes.
Making Expression @deconstructible and not BaseExpression allows
interested parties to conform to the "expression" API even if they are
not deconstructible as it's only a requirement for expressions allowed
in Model fields and meta options (e.g. constraints, indexes).
Thanks Phillip Cutter for the report.
This also fixes a performance regression in bbf141bcdc31f1324048af9233583a523ac54c94.
This issue started manifesting itself when nesting a combined subquery
relying on exclude() since 8593e162c9cb63a6c0b06daf045bc1c21eb4d7c1 but
sql.Query.combine never properly handled subqueries outer refs in the
first place, see QuerySetBitwiseOperationTests.test_subquery_aliases()
(refs #27149).
Thanks Raffaele Salmaso for the report.
This also replaces assertQuerysetEqual() to
assertSequenceEqual()/assertCountEqual() where appropriate.
Co-authored-by: Peter Inglesby <peter.inglesby@gmail.com>
Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>
As mentioned in the pre-existing split_exclude() docstring EXISTS is
easier to optimize for query planers and circumvents the IN (NULL)
handling issue.
By making Query subclass BaseExpression in
35431298226165986ad07e91f9d3aca721ff38ec the former defined it's
identity based off _construct_args which is not appropriate.
On CockroachDB, primary key values stored in these fields are larger
than they accept. Fixes:
queries.test_bulk_update.BulkUpdateNoteTests.test_multiple_fields,
queries.test_bulk_update.BulkUpdateNoteTests.test_inherited_fields, and
queries.tests.RelatedLookupTypeTests.test_values_queryset_lookup.
QuerySet.alias() allows creating reusable aliases for expressions that
don't need to be selected but are used for filtering, ordering, or as
a part of complex expressions.
Thanks Simon Charette for reviews.
Thanks to Adam Johnson, Carlton Gibson, Mariusz Felisiak, and Raphael
Michel for mentoring this Google Summer of Code 2019 project and
everyone else who helped with the patch.
Special thanks to Mads Jensen, Nick Pope, and Simon Charette for
extensive reviews.
Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>
Now that order_by() has expression support passing RawSQL() can achieve
the same result.
This was also already supported through QuerySet.extra(order_by) for
years but this API is more or less deprecated at this point.
