fix add_edge_to_view leaving edge_id to -1 in SQL

src/tracksdata/graph/_graph_view.py

@@ -798,6 +798,11 @@ def _add_edge_local(self, source_id: int, target_id: int) -> int:
                 if c in df.columns
             ]
             attrs = df.filter(pl.col(DEFAULT_ATTR_KEYS.EDGE_ID) == parent_edge_id).drop(drop_cols).rows(named=True)[0]
+            # A rustworkx-family root shares its payload, EDGE_ID included; other backends
+            # hand back a plain dict, so stamp the root edge id explicitly (as `bulk_add_edges`
+            # does). Otherwise the local edge keeps the -1 placeholder and disagrees with
+            # `_edge_map_to_root`, so reads by edge id find no row.
+            attrs[DEFAULT_ATTR_KEYS.EDGE_ID] = parent_edge_id
 
         local_edge_id = self.rx_graph.add_edge(
             self._map_to_local(source_id),

src/tracksdata/graph/_test/test_subgraph.py

@@ -1648,6 +1648,23 @@ def test_add_edge_to_view_basic(graph_backend: BaseGraph) -> None:
     assert row["weight"].item() == 0.5
 
 
+def test_add_edge_to_view_keeps_edge_id(graph_backend: BaseGraph) -> None:
+    """A revived edge's local row must carry the root edge id, so reads by id work."""
+    graph_backend.add_edge_attr_key("weight", pl.Float64)
+
+    n0 = graph_backend.add_node({"t": 0})
+    n1 = graph_backend.add_node({"t": 1})
+    root_edge_id = graph_backend.add_edge(n0, n1, {"weight": 1.5})
+
+    view = graph_backend.filter().subgraph()
+    view.remove_edge_from_view(n0, n1)
+    view.add_edge_to_view(n0, n1)
+
+    assert view.edge_id(n0, n1) == root_edge_id
+    assert view.edge_attrs(attr_keys=["weight"])[DEFAULT_ATTR_KEYS.EDGE_ID].to_list() == [root_edge_id]
+    assert view.edges[root_edge_id]["weight"] == 1.5
+
+
 def test_add_edge_to_view_validation(graph_backend: BaseGraph) -> None:
     """Bad inputs raise ValueError; sync=False raises RuntimeError."""
     graph_backend.add_node_attr_key("x", pl.Float64)