Fixed #35074 -- Fixed adding/removing indexes when spatial_index is changed on MySQL, PostgreSQL, and Oracle.

Co-authored-by: Mário Falcão <mario@falcao.dev>

django/contrib/gis/db/backends/mysql/schema.py

@@ -58,6 +58,43 @@ class MySQLGISSchemaEditor(DatabaseSchemaEditor):
 
         super().remove_field(model, field)
 
+    def _alter_field(
+        self,
+        model,
+        old_field,
+        new_field,
+        old_type,
+        new_type,
+        old_db_params,
+        new_db_params,
+        strict=False,
+    ):
+        super()._alter_field(
+            model,
+            old_field,
+            new_field,
+            old_type,
+            new_type,
+            old_db_params,
+            new_db_params,
+            strict=strict,
+        )
+
+        old_field_spatial_index = (
+            isinstance(old_field, GeometryField)
+            and old_field.spatial_index
+            and not old_field.null
+        )
+        new_field_spatial_index = (
+            isinstance(new_field, GeometryField)
+            and new_field.spatial_index
+            and not new_field.null
+        )
+        if not old_field_spatial_index and new_field_spatial_index:
+            self.execute(self._create_spatial_index_sql(model, new_field))
+        elif old_field_spatial_index and not new_field_spatial_index:
+            self.execute(self._delete_spatial_index_sql(model, old_field))
+
     def _create_spatial_index_name(self, model, field):
         return "%s_%s_id" % (model._meta.db_table, field.column)
 

django/contrib/gis/db/backends/oracle/schema.py

@@ -98,6 +98,39 @@ class OracleGISSchemaEditor(DatabaseSchemaEditor):
             self.execute(sql)
         self.geometry_sql = []
 
+    def _alter_field(
+        self,
+        model,
+        old_field,
+        new_field,
+        old_type,
+        new_type,
+        old_db_params,
+        new_db_params,
+        strict=False,
+    ):
+        super()._alter_field(
+            model,
+            old_field,
+            new_field,
+            old_type,
+            new_type,
+            old_db_params,
+            new_db_params,
+            strict=strict,
+        )
+
+        old_field_spatial_index = (
+            isinstance(old_field, GeometryField) and old_field.spatial_index
+        )
+        new_field_spatial_index = (
+            isinstance(new_field, GeometryField) and new_field.spatial_index
+        )
+        if not old_field_spatial_index and new_field_spatial_index:
+            self.execute(self._create_spatial_index_sql(model, new_field))
+        elif old_field_spatial_index and not new_field_spatial_index:
+            self.execute(self._delete_spatial_index_sql(model, old_field))
+
     def _create_spatial_index_name(self, model, field):
         # Oracle doesn't allow object names > 30 characters. Use this scheme
         # instead of self._create_index_name() for backwards compatibility.

django/contrib/gis/db/backends/postgis/schema.py

@@ -1,3 +1,4 @@
+from django.contrib.gis.db.models import GeometryField
 from django.db.backends.postgresql.schema import DatabaseSchemaEditor
 from django.db.models.expressions import Col, Func
 
@@ -58,6 +59,39 @@ class PostGISSchemaEditor(DatabaseSchemaEditor):
             [],
         )
 
+    def _alter_field(
+        self,
+        model,
+        old_field,
+        new_field,
+        old_type,
+        new_type,
+        old_db_params,
+        new_db_params,
+        strict=False,
+    ):
+        super()._alter_field(
+            model,
+            old_field,
+            new_field,
+            old_type,
+            new_type,
+            old_db_params,
+            new_db_params,
+            strict=strict,
+        )
+
+        old_field_spatial_index = (
+            isinstance(old_field, GeometryField) and old_field.spatial_index
+        )
+        new_field_spatial_index = (
+            isinstance(new_field, GeometryField) and new_field.spatial_index
+        )
+        if not old_field_spatial_index and new_field_spatial_index:
+            self.execute(self._create_spatial_index_sql(model, new_field))
+        elif old_field_spatial_index and not new_field_spatial_index:
+            self.execute(self._delete_spatial_index_sql(model, old_field))
+
     def _create_spatial_index_name(self, model, field):
         return self._create_index_name(model._meta.db_table, [field.column], "_id")
 
@@ -84,3 +118,7 @@ class PostGISSchemaEditor(DatabaseSchemaEditor):
             opclasses=opclasses,
             expressions=expressions,
         )
+
+    def _delete_spatial_index_sql(self, model, field):
+        index_name = self._create_spatial_index_name(model, field)
+        return self._delete_index_sql(model, index_name)

tests/gis_tests/gis_migrations/test_operations.py

@@ -92,6 +92,20 @@ class OperationTestCase(TransactionTestCase):
         else:
             self.assertIn([column], [c["columns"] for c in constraints.values()])
 
+    def assertSpatialIndexNotExists(self, table, column, raster=False):
+        with connection.cursor() as cursor:
+            constraints = connection.introspection.get_constraints(cursor, table)
+        if raster:
+            self.assertFalse(
+                any(
+                    "st_convexhull(%s)" % column in c["definition"]
+                    for c in constraints.values()
+                    if c["definition"] is not None
+                )
+            )
+        else:
+            self.assertNotIn([column], [c["columns"] for c in constraints.values()])
+
     def alter_gis_model(
         self,
         migration_class,
@@ -239,6 +253,102 @@ class OperationTests(OperationTestCase):
         if connection.features.supports_raster:
             self.assertSpatialIndexExists("gis_neighborhood", "rast", raster=True)
 
+    @skipUnlessDBFeature("can_alter_geometry_field")
+    def test_alter_field_add_spatial_index(self):
+        if not self.has_spatial_indexes:
+            self.skipTest("No support for Spatial indexes")
+
+        self.alter_gis_model(
+            migrations.AddField,
+            "Neighborhood",
+            "point",
+            fields.PointField,
+            field_class_kwargs={"spatial_index": False},
+        )
+        self.assertSpatialIndexNotExists("gis_neighborhood", "point")
+
+        self.alter_gis_model(
+            migrations.AlterField,
+            "Neighborhood",
+            "point",
+            fields.PointField,
+            field_class_kwargs={"spatial_index": True},
+        )
+        self.assertSpatialIndexExists("gis_neighborhood", "point")
+
+    @skipUnlessDBFeature("can_alter_geometry_field")
+    def test_alter_field_remove_spatial_index(self):
+        if not self.has_spatial_indexes:
+            self.skipTest("No support for Spatial indexes")
+
+        self.assertSpatialIndexExists("gis_neighborhood", "geom")
+
+        self.alter_gis_model(
+            migrations.AlterField,
+            "Neighborhood",
+            "geom",
+            fields.MultiPolygonField,
+            field_class_kwargs={"spatial_index": False},
+        )
+        self.assertSpatialIndexNotExists("gis_neighborhood", "geom")
+
+    @skipUnlessDBFeature("can_alter_geometry_field")
+    @skipUnless(connection.vendor == "mysql", "MySQL specific test")
+    def test_alter_field_nullable_with_spatial_index(self):
+        if not self.has_spatial_indexes:
+            self.skipTest("No support for Spatial indexes")
+
+        self.alter_gis_model(
+            migrations.AddField,
+            "Neighborhood",
+            "point",
+            fields.PointField,
+            field_class_kwargs={"spatial_index": False, "null": True},
+        )
+        # MySQL doesn't support spatial indexes on NULL columns.
+        self.assertSpatialIndexNotExists("gis_neighborhood", "point")
+
+        self.alter_gis_model(
+            migrations.AlterField,
+            "Neighborhood",
+            "point",
+            fields.PointField,
+            field_class_kwargs={"spatial_index": True, "null": True},
+        )
+        self.assertSpatialIndexNotExists("gis_neighborhood", "point")
+
+        self.alter_gis_model(
+            migrations.AlterField,
+            "Neighborhood",
+            "point",
+            fields.PointField,
+            field_class_kwargs={"spatial_index": False, "null": True},
+        )
+        self.assertSpatialIndexNotExists("gis_neighborhood", "point")
+
+    @skipUnlessDBFeature("can_alter_geometry_field")
+    def test_alter_field_with_spatial_index(self):
+        if not self.has_spatial_indexes:
+            self.skipTest("No support for Spatial indexes")
+
+        self.alter_gis_model(
+            migrations.AddField,
+            "Neighborhood",
+            "point",
+            fields.PointField,
+            field_class_kwargs={"spatial_index": True},
+        )
+        self.assertSpatialIndexExists("gis_neighborhood", "point")
+
+        self.alter_gis_model(
+            migrations.AlterField,
+            "Neighborhood",
+            "point",
+            fields.PointField,
+            field_class_kwargs={"spatial_index": True, "srid": 3086},
+        )
+        self.assertSpatialIndexExists("gis_neighborhood", "point")
+
     @skipUnlessDBFeature("supports_3d_storage")
     def test_add_3d_field_opclass(self):
         if not connection.ops.postgis: