LayerMapping unable to update PointFields with "unique" keyword parameter

[Agnès Haasser]

Hello,

I'm trying to use LayerMapping in order to import Geographic Data in my database, in "update" mode. That is, I use "unique" parameter to check if LayerMapping should update existing entries or create new ones:

lm = LayerMapping(
            target_class,
            path_to_my_shp_file,
            my_mapping,
            unique=tuple_of_django_fields,
        )
lm.save(strict=True, verbose=True)

When target_class has a geometry of type PointField, I get an error:

'Point' object is not iterable
Traceback (most recent call last):
  File "file_on_disk/sia/gis_import/views.py", line 12, in launch_import
    databatch.import_geographic_data()
  File "file_on_disk/sia/gis_import/models.py", line 66, in import_geographic_data
    lm.save(strict=True, verbose=True)
  File "file_on_disk/venv/lib/python3.11/site-packages/django/contrib/gis/utils/layermapping.py", line 728, in save
    _save()
  File "file_on_disk/venv/lib/python3.11/site-packages/django/contrib/gis/utils/layermapping.py", line 653, in _save
    for g in new:
TypeError: 'Point' object is not iterable

I'm using Django 5.2 so I have an older version of layermapping but it seems the bug is still here in present source code (6.2 is not out yet as I write this ticket):

​https://github.com/django/django/blob/ea9742c6d02edf64fc0969f21506f2048c976051/django/contrib/gis/utils/layermapping.py#L661-L663

[Jacob Walls]

Thanks, reproduced at 170975c5bdc3fc69b15e46f50df7b48eb9e1115c with this rough test:

tests/gis_tests/layermap/tests.py

@@ -102 +102 @@
         lm.save()
         self.assertEqual(City.objects.count(), 3)
 
+    def test_layermap_unique_update(self):
+        lm = LayerMapping(City, city_shp, city_mapping, unique="point")
+        lm.save()
+        # Update.
+        lm.save()
+
+        # some assertion about the correct result...
+
     def test_layermap_strict(self):
         "Testing the `strict` keyword, and import of a LineString shapefile."
         # When the `strict` keyword is set an error encountered will force

Would you like submit a PR?

[Agnès Haasser]

Yes I can submit a PR, I have already written a fix in my project.