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
36592	Incorrect warning when specifying a UniqueConstraint with SQLite and nulls_distinct=False	Russell Owen		"I am trying to create a UniqueConstraint with `nulls_distinct=False`. This will be used with sqlite for local use and tests, and postgresql for production.

When I migrate my sqlite database I get this warning:

{{{
SQLite does not support unique constraints with nulls distinct.
}}}


I suspect this is a bug, since I specified that nulls should not be distinct.

Note that I also get the same warning if I specify `nulls_distinct=True`, but in that case I expect to see it.

Here is the simplest model I could come up with that shows the issue:
{{{
class SimpleModel(models.Model):
    field_a = models.IntegerField(null=True)
    field_b = models.IntegerField(null=True)

    class Meta:
        constraints = [
            UniqueConstraint(
                name=""simple_unique_constraint"",
                fields=[""field_a"", ""field_b""],
                nulls_distinct=False,
            ),
        ]
}}}
The full warning I see on migration is:
{{{
WARNINGS:
dances.SimpleModel: (models.W047) SQLite does not support unique constraints with nulls distinct.
	HINT: A constraint won't be created. Silence this warning if you don't care about it.
}}}
and, as I said before, I get the same warning if I use `nulls_distinct=True` (which is when I expect to see the warning)."	Bug	new	Database layer (models, ORM)	5.2	Normal		SQLite UniqueConstraint		Unreviewed	0	0	0	0	0	0