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
36718	Enable JSON negative indexing for Oracle 21c+ using [last-N]	Clifford Gama	Clifford Gama	"Follow up to #36085 which added negative indexing for sqlite (as a new feature for 6.0).

While doing some reading on JSON queries on Oracle, I found that you [https://docs.oracle.com/en/database/oracle/oracle-database/21/adjsn/json-path-expressions.html can index elements from the right] by using `[last-N]`.

> An array index can also have the form last - N, where - is a minus sign (hyphen) and N is a literal whole number (0, 1, 2,…) that is no greater than the array size minus 1. The next-to-last array element can be referenced using index last-1, the second-to-last by index last-2, and so on. Whitespace surrounding the minus sign (hyphen) is ignored.

I think we can use this to support negative indexing on Oracle versions that support `[last-N]`. Currently, trying to do so raises a `NotSupportedError` per #36085 which was focused on sqlite.

I can't find Oracle release notes specifying when [last-N] indexing was added, but the note I quoted is only available in 21c+ docs. "	New feature	closed	Database layer (models, ORM)	dev	Normal	fixed	JSONField array negative indexing		Ready for checkin	1	0	0	0	0	0