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
24169	ArrayField can't use __contained_by or __overlap queries for CharField	Joel Burton	Marc Tamlyn <marc.tamlyn@…>	"ArrayField's lookup.py uses the @> operator for !__contains, the <@ operator for !__contained_by, and the && operator for !__overlap.

When the field uses CharField (Postgres' varchar()), !__contains works, but !__contained_by and !__overlap do not, as Postgres does not define <@ and && operators for an array of varchar[] (it does for text[]).

!__contains works because, in array.py, there is a custom lookup, ""ArrayOverlap"", the outputs a cast to cast the array query value to, say, ""::varchar(10)[]""

If there are similar custom lookups for !__contained_by and !__overlap, these then work.
"	Bug	closed	contrib.postgres	1.8alpha1	Normal	fixed			Accepted	1	0	0	0	0	0