从CTE到mySQL存储过程代码

Question

这是一个使用sql CTE创建包含关系的表的传递闭包的查询 用户之间。（图表的边缘）。 怎么能在mySQL中完成呢？

WITH RECURSIVE transitive_closure(a, b, distance, path_string) AS
( SELECT a, b, 1 AS distance,
         a || '.' || b || '.' AS path_string
  FROM edges
 WHERE a = 1 -- source

  UNION ALL

  SELECT tc.a, e.b, tc.distance + 1,
         tc.path_string || e.b || '.' AS path_string
  FROM edges AS e
  JOIN transitive_closure AS tc ON e.a = tc.b
 WHERE tc.path_string NOT LIKE '%' || e.b || '.%'
)
  SELECT * FROM transitive_closure
  ORDER BY a, b, distance;

或者至少找到两个节点之间的所有简单路径，而不为所有节点创建传递闭包。 代码取自：http://techportal.inviqa.com/2009/09/07/graphs-in-the-database-sql-meets-social-networks/