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
29338	Can't use OuterRef in union Subquery	Matthew Pava	Mariusz Felisiak	"When you make a QuerySet using the `union` method or the `|` operator, the QuerySet passed into the `union` method cannot reference `OuterRef` even when wrapped with `Subquery`.

For example:

{{{
cls = Document.objects.filter(
    checklist__isnull=False,
    part=OuterRef('id')
).values('checklist__customer', 'created')

ots = Document.objects.filter(
    ownershiptransfer__isnull=False,
    part=OuterRef('id')
).values('ownershiptransfer__ship_target__contact', 'created')

return self.annotate(
    owner=Subquery(cls.union(ots).values('owner')[:1])
)
}}}


Returns this error:

{{{
ValueError
This queryset contains a reference to an outer query and may only be used in a subquery.

}}}

I get the same error with this statement:

{{{
return self.annotate(
    owner=Subquery((cls | ots).values('owner')[:1])
)

}}}

(As an aside, I also get an error when I try to apply an `order_by` clause.)"	Bug	closed	Database layer (models, ORM)	dev	Normal	fixed		Jeff Can Sarıgöl InvalidInterrupt	Accepted	1	0	0	0	0	0