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.
- Validate filename returned by FileField.upload_to() not a filename
passed to the FileField.generate_filename() (upload_to() may
completely ignored passed filename).
- Allow relative paths (without dot segments) in the generated filename.
Thanks to Jakub Kleň for the report and review.
Thanks to all folks for checking this patch on existing projects.
Thanks Florian Apolloner and Markus Holtermann for the discussion and
implementation idea.
Regression in 0b79eb3691.
The 'db' and 'passwd' connection options have been deprecated, use
'database' and 'password' instead (available since mysqlclient >= 1.3.8).
This also allows the 'database' option in DATABASES['OPTIONS'] on MySQL.
Having lookups group by subquery right-hand-sides is likely unnecessary
in the first place but relatively large amount of work would be needed
to achieve that such as making Lookup instances proper resolvable
expressions.
Regression in 3543129822.
Thanks James A. Munsch for the report.
In Query.join() the argument reuse_with_filtered_relation was used to
determine whether to use == or .equals(). As this area of code is
related to aliases, we only expect an instance of Join or BaseTable to
be provided - the only two classes that provide .equals().
In both cases, the implementations of __eq__() and equals() are based
on use of the "identity" property. __eq__() performs an isinstance()
check first, returning NotImplemented if required. BaseTable.equals()
then does a straightforward equality check on "identity". Join.equals()
is a little bit different as it skips checking the last element of the
"identity" property: filtered_relation. This was only included
previously when the with_filtered_relation argument was True, impossible
since bbf141bcdc.
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 bbf141bcdc.
Regression in 3a505c70e7.
Nonlitteral right-hand-sides of lookups need to be wrapped in
parentheses to avoid operator precedence ambiguities.
Thanks Charles Lirsac for the detailed report.
This also renames the `asc` variable to `default_order`, markes the
`desc` variable as unused, fixes a typo in SQLCompiler.get_order_by()
docstring, and reorders some blocks in SQLCompiler._order_by_pairs().
This issue started manifesting itself when nesting a combined subquery
relying on exclude() since 8593e162c9 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.