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
33143	Block import-time queries	Adam Johnson	Florian Zimmermann	"It's possible to make ORM queries at import time. For example:

{{{
class Form(forms.Form):
    country = forms.ChoiceField(choices=[c.name for c in Country.objects.all()])
}}}

I see import time queries fairly frequently, and every time I have encountered them they were a mistake. They end up querying the database once when the web server starts and caching the data forever, which is never desired.

Python allows imports to happen at any time, so there's no way to detect when ""import time"" is over, and the app is really running. An inner import may cause a module to be first loaded during a web request.

I therefore propose we block queries until *after* the `AppConfig.ready()` phase. This would protect against most problems.

We could block until *before* `AppConfig.ready()`. Queries inside a `ready()` method kind-of imply the user knows that the query is one-off at startup. But we do encourage users to perform some imports within `ready()` methods such as for signal registration."	Cleanup/optimization	closed	Database layer (models, ORM)	dev	Normal	fixed			Ready for checkin	1	0	0	0	0	0