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
24154	Fix check_aggregate_support for Expressions	Josh Smeaton	Josh Smeaton	"The existing check_aggregate_support does not recursively check all sub-expressions. Further, there is currently no way for non-aggregate expressions to opt-in to backend checks.

Expressions should call a check_backend_support method (on the compiler or connection) passing itself. It should also pass all sub-expressions (get_source_expressions), so that we can recursively check for support.

Most expressions can be a no-op  if they know for certain that all backends will have support, like for the Col and Ref expressions. This will improve performance by removing quite a bit of method call overhead.

The backend will then throw an exception if there is no support for a particular combination."	Cleanup/optimization	closed	Database layer (models, ORM)	1.8alpha1	Normal	fixed			Accepted	1	0	0	1	0	0