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
25453	makemigrations suggestion seems to go against best practices	Benjamin Wohlwend	nobody	"When creating a migration that makes a formerly nullable field non-nullable, `makemigrations` has these suggestions:

{{{
You are trying to change the nullable field 'foo' on bar to non-nullable without a default; we can't do that (the database needs something to populate existing rows).
Please select a fix:
 1) Provide a one-off default now (will be set on all existing rows)
 2) Ignore for now, and let me handle existing rows with NULL myself (e.g. adding a RunPython or RunSQL operation in the new migration file before the AlterField operation)
 3) Quit, and let me add a default in models.py
}}}

The second option seems to suggest to add the `RunPython` operation in the same migration file as the `AlterField` operation, which is against best practices of splitting schema- and data-migrations.

This seems to be somewhat related to #24630, which updated the documentation to show how to split up the migration (albeit for a slightly different use case). I'm not sure how the output from `makemigrations` could be worded better, but it could e.g. link to the updated docs."	Cleanup/optimization	closed	Migrations	1.8	Normal	fixed		piquadrat@…	Ready for checkin	1	0	0	0	0	0