我有一个表,其中包括一个关键字段,一个跟随键和最多两个以前的键。如何根据下一个等于以下键的记录创建排序结果?
KEY,PRKEY1,PRKEY2,FLWKEY
-------------------------------
3701401,0000000,0000000,3701403
3701403,3701401,0000000,3701421
3701402,0000000,0000000,3701404
3701404,3701402,0000000,3701421
3701421,3701404,3701403,3701405
3701405,3701421,0000000,3701423
3701299,0000000,0000000,3701210
3701210,3701299,0000000,3702007
3702007,3701210,0000000,3701005
3701005,3702007,0000000,3701423
3701423,3701405,3701005,3701411
3701413,0000000,0000000,3701411
3701411,3701423,3701413,3701431
3701431,3701411,3701005,3701455
3701451,0000000,0000000,3701455
3701455,3701431,3701451,3701443
3701443,3701455,0000000,3701445
3701445,3701443,0000000,3701432
3701432,3701445,0000000,3701434
3701434,3701432,0000000,3701435
3701435,3701434,0000000,0000000
结果应如下所示:
KEY,PRKEY1,PRKEY2,FLWKEY
-------------------------------
3701401,0000000,0000000,3701403
3701403,3701401,0000000,3701421
3701421,3701404,3701403,3701405
3701405,3701421,0000000,3701423
3701423,3701405,3701005,3701411
3701411,3701423,3701413,3701431
3701431,3701411,3701005,3701455
3701455,3701431,3701451,3701443
3701443,3701455,0000000,3701445
3701445,3701443,0000000,3701432
3701432,3701445,0000000,3701434
3701434,3701432,0000000,3701435
3701435,3701434,0000000,0000000
提前致谢。我只有大约5万条记录来解决这个问题。
答案 0 :(得分:3)
WITH q (key, prkey1, prkey2, flwkey, init, lvl) AS
(
SELECT *, key, 1
FROM mytable
WHERE key = 3701401
UNION ALL
SELECT mt.*, q.init, q.lvl + 1
FROM q
JOIN mytable mt
ON mt.key = q.flwkey
)
SELECT key, prkey1, prkey2, flwkey
FROM q
ORDER BY
init, lvl
这是一个链接列表,您需要在递归CTE中遍历。
sqlfiddle here