Fixed #28738 -- Added the GeometryDistance function.

5 files changed, 19 insertions, 11 deletions

diff --git a/django/contrib/gis/db/backends/base/operations.py b/django/contrib/gis/db/backends/base/operations.py
index 860748cc9d..4a2245680f 100644
--- a/django/contrib/gis/db/backends/base/operations.py
+++ b/django/contrib/gis/db/backends/base/operations.py
@@ -40,10 +40,10 @@ class BaseSpatialOperations:
     unsupported_functions = {
         'Area', 'AsGeoJSON', 'AsGML', 'AsKML', 'AsSVG', 'Azimuth',
         'BoundingCircle', 'Centroid', 'Difference', 'Distance', 'Envelope',
-        'GeoHash', 'Intersection', 'IsValid', 'Length', 'LineLocatePoint',
-        'MakeValid', 'MemSize', 'NumGeometries', 'NumPoints', 'Perimeter',
-        'PointOnSurface', 'Reverse', 'Scale', 'SnapToGrid', 'SymDifference',
-        'Transform', 'Translate', 'Union',
+        'GeoHash', 'GeometryDistance', 'Intersection', 'IsValid', 'Length',
+        'LineLocatePoint', 'MakeValid', 'MemSize', 'NumGeometries',
+        'NumPoints', 'Perimeter', 'PointOnSurface', 'Reverse', 'Scale',
+        'SnapToGrid', 'SymDifference', 'Transform', 'Translate', 'Union',
     }
 
     # Constructors
diff --git a/django/contrib/gis/db/backends/mysql/operations.py b/django/contrib/gis/db/backends/mysql/operations.py
index 1ac8055071..e765e4d879 100644
--- a/django/contrib/gis/db/backends/mysql/operations.py
+++ b/django/contrib/gis/db/backends/mysql/operations.py
@@ -54,9 +54,9 @@ class MySQLOperations(BaseSpatialOperations, DatabaseOperations):
     def unsupported_functions(self):
         unsupported = {
             'AsGML', 'AsKML', 'AsSVG', 'Azimuth', 'BoundingCircle',
-            'ForcePolygonCW', 'LineLocatePoint', 'MakeValid', 'MemSize',
-            'Perimeter', 'PointOnSurface', 'Reverse', 'Scale', 'SnapToGrid',
-            'Transform', 'Translate',
+            'ForcePolygonCW', 'GeometryDistance', 'LineLocatePoint',
+            'MakeValid', 'MemSize', 'Perimeter', 'PointOnSurface', 'Reverse',
+            'Scale', 'SnapToGrid', 'Transform', 'Translate',
         }
         if self.connection.mysql_is_mariadb:
             unsupported.update({'GeoHash', 'IsValid'})
diff --git a/django/contrib/gis/db/backends/oracle/operations.py b/django/contrib/gis/db/backends/oracle/operations.py
index df052d74fc..f41ce0ed64 100644
--- a/django/contrib/gis/db/backends/oracle/operations.py
+++ b/django/contrib/gis/db/backends/oracle/operations.py
@@ -107,8 +107,8 @@ class OracleOperations(BaseSpatialOperations, DatabaseOperations):
 
     unsupported_functions = {
         'AsGeoJSON', 'AsKML', 'AsSVG', 'Azimuth', 'ForcePolygonCW', 'GeoHash',
-        'LineLocatePoint', 'MakeValid', 'MemSize', 'Scale', 'SnapToGrid',
-        'Translate',
+        'GeometryDistance', 'LineLocatePoint', 'MakeValid', 'MemSize',
+        'Scale', 'SnapToGrid', 'Translate',
     }
 
     def geo_quote_name(self, name):
diff --git a/django/contrib/gis/db/backends/spatialite/operations.py b/django/contrib/gis/db/backends/spatialite/operations.py
index bbce44b9df..a1c049b562 100644
--- a/django/contrib/gis/db/backends/spatialite/operations.py
+++ b/django/contrib/gis/db/backends/spatialite/operations.py
@@ -79,7 +79,7 @@ class SpatiaLiteOperations(BaseSpatialOperations, DatabaseOperations):
 
     @cached_property
     def unsupported_functions(self):
-        unsupported = {'BoundingCircle', 'MemSize'}
+        unsupported = {'BoundingCircle', 'GeometryDistance', 'MemSize'}
         if not self.lwgeom_version():
             unsupported |= {'Azimuth', 'GeoHash', 'IsValid', 'MakeValid'}
         return unsupported
diff --git a/django/contrib/gis/db/models/functions.py b/django/contrib/gis/db/models/functions.py
index c1ae4ae445..a79067a45a 100644
--- a/django/contrib/gis/db/models/functions.py
+++ b/django/contrib/gis/db/models/functions.py
@@ -48,7 +48,7 @@ class GeoFuncMixin:
         return self.source_expressions[self.geom_param_pos[0]].field
 
     def as_sql(self, compiler, connection, function=None, **extra_context):
-        if not self.function and not function:
+        if self.function is None and function is None:
             function = connection.ops.spatial_function_name(self.name)
         return super().as_sql(compiler, connection, function=function, **extra_context)
 
@@ -299,6 +299,14 @@ class GeoHash(GeoFunc):
         return clone.as_sql(compiler, connection, **extra_context)
 
 
+class GeometryDistance(GeoFunc):
+    output_field = FloatField()
+    arity = 2
+    function = ''
+    arg_joiner = ' <-> '
+    geom_param_pos = (0, 1)
+
+
 class Intersection(OracleToleranceMixin, GeomOutputGeoFunc):
     arity = 2
     geom_param_pos = (0, 1)