WITH RECURSIVE transitive_closure(a, b, distance, path_string) AS
( SELECT a, b, 1 AS distance,
         a || '.' || b || '.' AS path_string,
         b AS direct_connection
    FROM edges2
   WHERE a = 1 -- set the starting node

   UNION ALL

  SELECT tc.a, e.b, tc.distance + 1,
         tc.path_string || e.b || '.' AS path_string,
         tc.direct_connection
    FROM edges2 AS e
    JOIN transitive_closure AS tc ON e.a = tc.b
   WHERE tc.path_string NOT LIKE '%' || e.b || '.%'
     AND tc.distance < 3
)
SELECT * FROM transitive_closure
--WHERE b=3  -- set the target node
ORDER BY a,b,distance

如何在MySql中运行此查询？

它会显示如下错误消息：

＃1064-您的SQL语法有误；检查与您的MySQL服务器版本相对应的手册以获取正确的语法，以在“ RECURSIVEtransiveive_closure（a，b，distance，path_string）AS（SELECT a，b，1 A''第1行附近使用）