Allows expected behavior when cast to str, also matching behaviour of
created instances with those fetched from the DB.
Thanks to Simon Charette, Nick Pope, and Shai Berger for reviews.
This required moving the entirety of DELETE SQL generation to the
compiler where it should have been in the first place and implementing
a specialized compiler on MySQL/MariaDB.
The MySQL compiler relies on the "DELETE table FROM table JOIN" syntax
for queries spanning over multiple tables.
Added internal interface to QuerySet that allows to defer next filter
call till .query is accessed. Used it to optimize prefetch_related().
Thanks Simon Charette for the review.
Reduced the number of queries required when performing cascade deletion
for a model referenced multiple time by another one by performing an
union of reference lookups.
Changed __eq__ to return NotImplemented instead of False if compared to
an object of the same type, as is recommended by the Python data model
reference. Now these models can be compared to ANY (or other objects
with __eq__ overwritten) without returning False automatically.
Use pre-existing select fields (and thereby GROUP BY fields) from
subquery if they were specified, instead of always defaulting to pk.
Thanks Aur Saraf for the report and Simon Charette for guidance.
SQLite doesn't repoint table aliases in partial index conditions on table
rename which breaks the documented table alteration procedure.
Thanks Pēteris Caune for the report.
These classes can serve as a base class for user enums, supporting
translatable human-readable names, or names automatically inferred
from the enum member name.
Additional properties make it easy to access the list of names, values
and display labels.
Thanks to the following for ideas and reviews:
Carlton Gibson, Fran Hrženjak, Ian Foote, Mariusz Felisiak, Shai Berger.
Co-authored-by: Shai Berger <shai@platonix.com>
Co-authored-by: Nick Pope <nick.pope@flightdataservices.com>
Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>
OuterRef right hand sides have to be nested, just like F rhs have to,
during the subquery pushdown split_exclude performs to ensure they are
resolved against the outer query aliases.
Expressions should never be prepared as other Lookup.get_prep_lookup
implementations hint at by returning early on the presence of the
resolve_expression attribute.
The previous solution was only handling lookups against related fields
pointing at AutoFields and would break for foreign keys to other fields.
It was also causing bidirectional coupling between model fields and
expressions which the method level import of OuterRef was a symptom of.
This allows using expressions that have an output_field that is a
BooleanField to be used directly in a queryset filters, or in the
When() clauses of a Case() expression.
Thanks Josh Smeaton, Tim Graham, Simon Charette, Mariusz Felisiak, and
Adam Johnson for reviews.
Co-Authored-By: NyanKiyoshi <hello@vanille.bid>
This reduces duplication by allowing AutoField, BigAutoField and
SmallAutoField to inherit from IntegerField, BigIntegerField and
SmallIntegerField respectively. Doing so also allows for enabling the
max_length warning check and minimum/maximum value validation for auto
fields, as well as providing a mixin that can be used for other possible
future auto field types such as a theoretical UUIDAutoField.
Made sql.Where resolve lhs of its child nodes. This is necessary to
allow filter lookups against nested subquery expressions to properly
resolve their OuterRefs to Cols.
Thanks Oskar Persson for the simplified test case.
Oracle requires the EXISTS expression to be wrapped in a CASE WHEN in
the following cases.
1. When part of a SELECT clause.
2. When part of a ORDER BY clause.
3. When compared against another expression in the WHERE clause.
This commit moves the systematic CASE WHEN wrapping of Exists.as_oracle
to contextual .select_format, Lookup.as_oracle, and OrderBy.as_oracle
methods in order to avoid unnecessary wrapping.