DROP PROPERTY GRAPH IF EXISTS kg2;
DROP TABLE IF EXISTS kv2, ke2 CASCADE;

CREATE TABLE kv2 (id int PRIMARY KEY, tag int, name text);   -- key is a genuine PK
CREATE TABLE ke2 (id int PRIMARY KEY, src int, dst int);
INSERT INTO kv2 VALUES (1,7,'a'), (2,7,'b'), (3,9,'c');
INSERT INTO ke2 VALUES (1, 7, 9);                            -- exactly ONE edge
CREATE PROPERTY GRAPH kg2
  VERTEX TABLES (kv2 KEY (id))
  EDGE TABLES (ke2 KEY (id) SOURCE KEY (src) REFERENCES kv2 (tag)
                            DESTINATION KEY (dst) REFERENCES kv2 (tag));
SELECT * FROM GRAPH_TABLE (kg2 MATCH (a IS kv2)-[x IS ke2]->(b IS kv2)
                           COLUMNS (a.name AS src_name, b.name AS dst_name));
