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
37322	Saving to SpatialField(srid=None) persists NULL instead of raising an error	Jacob Walls		"At least one user has tried to use spatial fields with a definition of `srid=None`, see [https://forum.djangoproject.com/t/rasterfield-with-srid-none-dont-force-transform/28745 forum]. I'm pretty certain that's invalid usage.

Django can't create a migration to create such a spatial column with `srid=None`[0], but you can imagine a user trying this with an unmanaged model.

In Django 6.0, trying to save values to such a field raised `DatabaseError`, because `None` compiled to the string `""None""` and crashed.

After 1a8fd5cf75bf855852f6bc2f75c3da9f7b145669 (#36727, Django 6.1) implemented proper parameterization for `srid` values in spatial queries, `None` compiled to `NULL`, which zeroed out the value (because `ST_Transform(..., NULL)` returns `NULL`).

Suggesting we throw an error for this case in Python before letting the query persist `NULL`.

Test case [https://dryorm.xterm.info/no-srid-silent-failure on DryORM]:
(You could probably construct a version of this test case using only `output_field=GeometryField(srid=None))`.)
{{{#!py
from django.contrib.gis.db import models
from django.contrib.gis.geos import GEOSGeometry
from django.db.models.expressions import Value

class Person(models.Model):
    # Create this field without srid=None for the sake of creating
    # a working migration.
    home = models.PointField(null=True)


def run():
    # Because Django migrated this model, restore the model field
    # to have srid=None, to simulate an unmanaged model.
    home = Person._meta.get_fields()[1]
    home.srid = None

    me = Person.objects.create()
    me.home = GEOSGeometry(""POINT(1 1)"", srid=4326)
    me.save()
    me.refresh_from_db()
    assert me.home  # raises
}}}

Rerunning that snippet on 6.0 gives a `DatabaseError` instead. We can raise an error in the ORM layer instead.

----
[0] At least on PostGIS, because of a `%d` placeholder. I can check other backends shortly."	Bug	new	GIS	6.1	Release blocker		srid	Simon Charette	Unreviewed	0	0	0	0	0	0