id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
28658	Move DISTINCT handling to the Aggregate base class.	Simon Charette	Simon Charette	"Django ships with a few `Aggregate` subclasses that expose a `distinct` kwarg in order to inject a `DISTINCT` clause on compilation.

Since `DISTINCT` is repeatedly used by subclasses and likely to be useful for custom `Aggregate` subclasses (PostgreSQL supports `DISTINCT` on all aggregate functions, SQLite on all aggregates with a single argument, ...) I suggest we handle it in the `Aggregate` base class.

We should be able to rely on `DatebaseOperations.check_expression_support` to prevent `distinct=True` from being passed to aggregates not supporting it on a backend basis."	Cleanup/optimization	closed	Database layer (models, ORM)	dev	Normal	fixed			Accepted	1	0	0	0	0	0