Refs #33783 -- Added IsEmpty GIS database function and __isempty lookup on SpatiaLite.

django/contrib/gis/db/backends/spatialite/operations.py

@@ -82,7 +82,7 @@ class SpatiaLiteOperations(BaseSpatialOperations, DatabaseOperations):
 
     @cached_property
     def unsupported_functions(self):
-        unsupported = {"GeometryDistance", "IsEmpty", "MemSize"}
+        unsupported = {"GeometryDistance", "MemSize"}
         if not self.geom_lib_version():
             unsupported |= {"Azimuth", "GeoHash", "MakeValid"}
         if self.spatial_version < (5, 1):

docs/ref/contrib/gis/db-api.txt

@@ -359,7 +359,7 @@ Lookup Type                        PostGIS    Oracle   MariaDB    MySQL [#]_   S
 :lookup:`equals`                   X          X        X          X            X          C
 :lookup:`exact <same_as>`          X          X        X          X            X          B
 :lookup:`intersects`               X          X        X          X            X          B
-:lookup:`isempty`                  X
+:lookup:`isempty`                  X                                           X
 :lookup:`isvalid`                  X          X        X (≥ 11.7) X            X
 :lookup:`overlaps`                 X          X        X          X            X          B
 :lookup:`relate`                   X          X        X                       X          C
@@ -408,7 +408,7 @@ Function                              PostGIS  Oracle         MariaDB      MySQL
 :class:`FromWKT`                      X        X              X            X           X
 :class:`GeoHash`                      X                       X (≥ 11.7)   X           X (LWGEOM/RTTOPO)
 :class:`Intersection`                 X        X              X            X           X
-:class:`IsEmpty`                      X
+:class:`IsEmpty`                      X                                                X
 :class:`IsValid`                      X        X              X (≥ 11.7)   X           X
 :class:`Length`                       X        X              X            X           X
 :class:`LineLocatePoint`              X                                                X

docs/ref/contrib/gis/functions.txt

@@ -438,11 +438,16 @@ intersection between them.
 
 .. class:: IsEmpty(expr)
 
-*Availability*: `PostGIS <https://postgis.net/docs/ST_IsEmpty.html>`__
+*Availability*: `PostGIS <https://postgis.net/docs/ST_IsEmpty.html>`__,
+SpatiaLite
 
 Accepts a geographic field or expression and tests if the value is an empty
 geometry. Returns ``True`` if its value is empty and ``False`` otherwise.
 
+.. versionchanged:: 5.2
+
+    Support for SpatiaLite was added.
+
 ``IsValid``
 ===========
 

docs/ref/contrib/gis/geoquerysets.txt

@@ -362,7 +362,8 @@ SpatiaLite  ``Intersects(poly, geom)``
 ``isempty``
 -----------
 
-*Availability*: `PostGIS <https://postgis.net/docs/ST_IsEmpty.html>`__
+*Availability*: `PostGIS <https://postgis.net/docs/ST_IsEmpty.html>`__,
+SpatiaLite
 
 Tests if the geometry is empty.
 
@@ -372,6 +373,10 @@ Example::
 
 .. fieldlookup:: isvalid
 
+.. versionchanged:: 5.2
+
+    Support for SpatiaLite was added.
+
 ``isvalid``
 -----------
 

docs/releases/5.2.txt

@@ -108,6 +108,10 @@ Minor features
   :class:`~django.contrib.gis.db.models.functions.IsValid` database functions
   are now supported on MariaDB 11.7+.
 
+* The :lookup:`isempty` lookup and
+  :class:`~django.contrib.gis.db.models.functions.IsEmpty` expression are now
+  supported on SpatiaLite.
+
 :mod:`django.contrib.messages`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

tests/gis_tests/geoapp/models.py

@@ -28,6 +28,13 @@ class City(NamedModel):
         app_label = "geoapp"
 
 
+class Town(NamedModel):
+    point = models.PointField(null=True)
+
+    class Meta:
+        app_label = "geoapp"
+
+
 # This is an inherited model from City
 class PennsylvaniaCity(City):
     county = models.CharField(max_length=30)

tests/gis_tests/geoapp/test_functions.py

@@ -11,7 +11,15 @@ from django.db.models import IntegerField, Sum, Value
 from django.test import TestCase, skipUnlessDBFeature
 
 from ..utils import FuncTestMixin
-from .models import City, Country, CountryWebMercator, ManyPointModel, State, Track
+from .models import (
+    City,
+    Country,
+    CountryWebMercator,
+    ManyPointModel,
+    State,
+    Town,
+    Track,
+)
 
 
 class GISFunctionsTests(FuncTestMixin, TestCase):
@@ -413,7 +421,7 @@ class GISFunctionsTests(FuncTestMixin, TestCase):
                 self.assertIs(c.inter.empty, True)
 
     @skipUnlessDBFeature("supports_empty_geometries", "has_IsEmpty_function")
-    def test_isempty(self):
+    def test_isempty_empty_geometry(self):
         empty = City.objects.create(name="Nowhere", point=Point(srid=4326))
         City.objects.create(name="Somewhere", point=Point(6.825, 47.1, srid=4326))
         self.assertSequenceEqual(
@@ -424,6 +432,29 @@ class GISFunctionsTests(FuncTestMixin, TestCase):
         )
         self.assertSequenceEqual(City.objects.filter(point__isempty=True), [empty])
 
+    @skipUnlessDBFeature("has_IsEmpty_function")
+    def test_isempty_null_geometry(self):
+        null_geometry = Town.objects.create(name="Nowhere", point=None)
+        Town.objects.create(name="Somewhere", point=Point(6.825, 47.1, srid=4326))
+        if connection.ops.spatialite:
+            self.assertSequenceEqual(
+                Town.objects.annotate(isempty=functions.IsEmpty("point")).filter(
+                    isempty=True
+                ),
+                [null_geometry],
+            )
+            self.assertSequenceEqual(
+                Town.objects.filter(point__isempty=True), [null_geometry]
+            )
+        else:
+            self.assertSequenceEqual(
+                Town.objects.annotate(isempty=functions.IsEmpty("point")).filter(
+                    isempty=True
+                ),
+                [],
+            )
+            self.assertSequenceEqual(Town.objects.filter(point__isempty=True), [])
+
     @skipUnlessDBFeature("has_IsValid_function")
     def test_isvalid(self):
         valid_geom = fromstr("POLYGON((0 0, 0 1, 1 1, 1 0, 0 0))")