Question

我希望这不是重复，我会发布一些帖子，但无法弄清楚如何解决这个问题。

我有一张这样的表

CREATE TABLE yo (ad INTEGER PRIMARY KEY, pa INTEGER, pd INTEGER);

INSERT INTO yo VALUES
(1,1,1),(2,1,3),(3,1,4),(4,3,5),(5,4,2),(6,3,8),(7,1,9),(8,6,7),(9,3,6);
.header on
.mode column yo
select * from yo;

ad          pa          pd
----------  ----------  ----------
1           1           1
2           1           3
3           1           4
4           3           5
5           4           2
6           3           8
7           1           9
8           6           7
9           3           6

我可以使用CTE创建一个临时表来获取col'pd'的深度级别，就像这样

CREATE table ui AS 
 WITH RECURSIVE ui(a,l) AS
 ( VALUES(1,0)
    UNION ALL
    SELECT yo.ad, ui.l+1
      FROM yo JOIN ui ON yo.pa=ui.a
      WHERE yo.pa!=yo.ad
    ORDER BY 2 desc
  )
  SELECT a,l FROM ui;

select * from ui;

a           l
----------  ----------
1           0
2           1
3           1
4           2
5           3
6           2
8           3
9           2
7           1

然后我想添加一个col来表'yo'并在那里输入ui.l

ALTER TABLE yo ADD COLUMN lv INTEGER;
UPDATE yo SET lv=
  (SELECT ui.l
   FROM ui
   WHERE ui.a=yo.ad);

select * from yo;
ad          pa          pd          lv
----------  ----------  ----------  ----------
1           1           1           0
2           1           3           1
3           1           4           1
4           3           5           2
5           4           2           3
6           3           8           2
7           1           9           1
8           6           7           3
9           3           6           2

一切正常。现在我想在1个请求中组合临时表'ui'create和table'yo'更新？

我尝试了许多组合回合无法找到解决方案，我确定这很明显，但我还不够流利。

CTE创建应该在UPDATE之前，如

How to use CTE's with update/delete on SQLite?

或者应该将CTE计算到UPDATE中的选择

提前填写任何帮助

干杯，披

Answer 1

这有效：

WITH RECURSIVE ui(a,l) AS
( VALUES(1,0)
   UNION ALL
   SELECT yo.ad, ui.l+1
     FROM yo JOIN ui ON yo.pa=ui.a
     WHERE yo.pa!=yo.ad
   ORDER BY 2 desc
 )
UPDATE yo SET lv=
 (SELECT ui.l
  FROM ui
  WHERE ui.a=yo.ad);

这也有效：

UPDATE yo SET lv=
  (WITH RECURSIVE ui(a,l) AS
   ( VALUES(1,0)
     UNION ALL
     SELECT yo.ad, ui.l+1
       FROM yo JOIN ui ON yo.pa=ui.a
       WHERE yo.pa!=yo.ad
     ORDER BY 2 desc
   )
   SELECT ui.l
   FROM ui
   WHERE ui.a=yo.ad
  );

带有UPDATE的sqlite CTE

1 个答案: