Specific process for geometries with Z or M coordinate with SpatiaLite dialect

doc/spatialite_tutorial.rst

@@ -54,7 +54,7 @@ Declare a Mapping
 Now that we have a working connection we can go ahead and create a mapping between
 a Python class and a database table::
 
-    >>> from sqlalchemy.ext.declarative import declarative_base
+    >>> from sqlalchemy.orm import declarative_base
     >>> from sqlalchemy import Column, Integer, String
     >>> from geoalchemy2 import Geometry
     >>>

geoalchemy2/types/dialects/sqlite.py

@@ -13,9 +13,16 @@ def bind_processor_process(spatial_type, bindvalue):
         else:
             return "SRID=%d;%s" % (bindvalue.srid, bindvalue.data)
     elif isinstance(bindvalue, WKBElement):
+        if bindvalue.srid == -1:
+            bindvalue.srid = spatial_type.srid
         # With SpatiaLite we use Shapely to convert the WKBElement to an EWKT string
         shape = to_shape(bindvalue)
-        return "SRID=%d;%s" % (bindvalue.srid, shape.wkt)
+        result = "SRID=%d;%s" % (bindvalue.srid, shape.wkt)
+        if shape.has_z:
+            # shapely.wkb.loads returns geom_type with a 'Z', for example, 'LINESTRING Z'
+            # which is a limitation with SpatiaLite. Hence, a temporary fix.
+            result = result.replace("Z ", "")
+        return result
     elif isinstance(bindvalue, RasterElement):
         return "%s" % (bindvalue.data)
     else:

tests/test_functional_sqlite.py

@@ -129,6 +129,41 @@ def test_explicit_schema(self, conn):
         # Drop the table
         t.drop(bind=conn)
 
+    def test_3d_geometry(self, conn, metadata):
+        # Define the table
+        col = Column(
+            "geom",
+            Geometry(geometry_type=None, srid=4326, spatial_index=False),
+            nullable=False,
+        )
+        t = Table(
+            "3d_geom_type",
+            metadata,
+            Column("id", Integer, primary_key=True),
+            col,
+        )
+
+        # Create the table
+        t.create(bind=conn)
+
+        # Should be 'LINESTRING Z (0 0 0, 1 1 1)'
+        # Read comments at geoalchemy2/types/dialects/sqlite.py#L22
+        elements = {"geom": "SRID=4326;LINESTRING (0 0 0, 1 1 1)"}
+        conn.execute(t.insert(), elements)
+
+        with pytest.raises((IntegrityError, OperationalError)):
+            with conn.begin_nested():
+                # This returns a NULL for the geom field.
+                conn.execute(t.insert(), [{"geom": "SRID=4326;LINESTRING Z (0 0 0, 1 1 1)"}])
+
+        results = conn.execute(t.select())
+        rows = results.fetchall()
+
+        assert len(rows) == 1
+
+        # Drop the table
+        t.drop(bind=conn)
+
 
 class TestIndex:
     @pytest.fixture