Add test and fix for issue #55

grand/backends/_sqlbackend.py

@@ -306,14 +306,14 @@ def all_edges_as_iterable(self, include_metadata: bool = False) -> Generator:
         """
 
         columns = [
-            self._node_table.c[self._edge_source_key],
-            self._node_table.c[self._edge_target_key],
+            self._edge_table.c[self._edge_source_key],
+            self._edge_table.c[self._edge_target_key],
         ]
 
         if include_metadata:
-            columns.append(self._node_table.c["_metadata"])
+            columns.append(self._edge_table.c["_metadata"])
 
-        sql = self._node_table.select().with_only_columns(columns)
+        sql = self._edge_table.select().with_only_columns(*columns)
         return self._connection.execute(sql).fetchall()
 
     def get_node_by_id(self, node_name: Hashable):
@@ -676,4 +676,4 @@ def commit(self):
         self._connection.commit()
 
     def close(self):
-        self._connection.close()
+        self._connection.close()

grand/backends/test_backends.py

@@ -131,30 +131,30 @@
         ),
     )
 
+
 # @pytest.mark.parametrize("backend", backend_test_params)
 class TestBackendPersistence:
     def test_sqlite_persistence(self):
         if not _CAN_IMPORT_SQL:
             return
 
         dbpath = "grand_peristence_test_temp.db"
-        url = "sqlite:///"+dbpath
+        url = "sqlite:///" + dbpath
 
-        #arrange
+        # arrange
         backend = SQLBackend(db_url=url, directed=True)
-        node0 = backend.add_node("A",{"foo":"bar"})
+        node0 = backend.add_node("A", {"foo": "bar"})
         backend.commit()
         backend.close()
-        #act
+        # act
         backend = SQLBackend(db_url=url, directed=True)
         nodes = list(backend.all_nodes_as_iterable())
-        #assert
+        # assert
         assert node0 in nodes
-        #cleanup
+        # cleanup
         os.remove(dbpath)
 
 
-
 @pytest.mark.parametrize("backend", backend_test_params)
 class TestBackend:
     def test_can_create(self, backend):
@@ -344,6 +344,12 @@ def test_can_get_edge_metadata(self, backend):
         G.nx.add_edge("foo", "bar", baz=True)
         assert list(G.nx.edges(data=True)) == [("foo", "bar", {"baz": True})]
 
+    def test_can_get_edges(self, backend):
+        backend, kwargs = backend
+        G = Graph(backend=backend(**kwargs))
+        G.nx.add_edge("foo", "bar", baz=True)
+        assert list(G.backend.all_edges_as_iterable()) == [("foo", "bar")]
+
     def test_edge_dne_raises(self, backend):
         backend, kwargs = backend
         G = Graph(backend=backend(**kwargs))