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
30547	Document what happens during model validation with Meta.constraints.	Dirk Groten	Swatantra	"The current [https://docs.djangoproject.com/en/2.2/ref/models/constraints/ constraints reference] does not mention whether or not a **ValidationError** is raised during model validation if a constraint fails. The documentation only mentions that a database constraint is created.

However, for the soon to be deprecated `unique_together`, there is a reference to model validation. 

As far as I can see, a `UniqueConstraint` causes `validate_unique()` to check for uniqueness and raises a **ValidationError**. But a `CheckConstraint` does not cause a **ValidationError** when the model is validated. I believe it's important to mention this in the documentation."	Cleanup/optimization	closed	Documentation	2.2	Normal	fixed	constraints, UniqueConstraint	Kevin Christopher Henry	Ready for checkin	1	0	0	0	1	0