Context Navigation

Changes between Version 1 and Version 2 of Ticket #32043, comment 3

v1	v2
16	16	If that's the case then I fear we cannot change the current behaviour without causing massive backward incompatibilities.
17	17
18		For example `filter(nullable_field=F('nullable_field'))` doesn't result in `WHERE nullable_field = nullable_field OR (nullable_field IS NULL ~~and~~ nullable_field IS NULL)` so making this change only for resolved `OuterRef` would make the current behaviour even more inconsistent. The ORM does a relatively good job at abstracting the triple-boolean logic of SQL when provided literal values (e.g. `None` handling in `exclude()`) but it doesn't deal with nullable expressions for performance reasons (hard to determine if complex expressions are nullable and `OR` clauses required for `IS NULL` makes the job of the query planner harder).
	18	For example `filter(nullable_field=F('nullable_field'))` doesn't result in `WHERE nullable_field = nullable_field OR (nullable_field IS NULL AND nullable_field IS NULL)` so making this change only for resolved `OuterRef` would make the current behaviour even more inconsistent. The ORM does a relatively good job at abstracting the triple-boolean logic of SQL when provided literal values (e.g. `None` handling in `exclude()`) but it doesn't deal with nullable expressions for performance reasons (hard to determine if complex expressions are nullable and `OR` clauses required for `IS NULL` makes the job of the query planner harder).