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sql - With 子句：嵌套树

问题描述

我有一个兄弟排序的树层次结构。我需要添加对其他树的引用。

这是数据：

drop table if exists org; CREATE TABLE org(id int primary key, name text, boss int, sibling int, ref int) without rowid;
INSERT INTO org VALUES(0, 'Alice', NULL, null, null);
INSERT INTO org VALUES(1, 'Bob', 0, null, null);
INSERT INTO org VALUES(2, 'Cindy', 0, 1, null);
INSERT INTO org VALUES(3, 'Dave', 1, 4, 7);
INSERT INTO org VALUES(4, 'Emma', 1, null, null);
INSERT INTO org VALUES(5, 'Fred', 2, null, null);
INSERT INTO org VALUES(6, 'Gail', 2, 5, null);
INSERT INTO org VALUES(7, 'Helen', NULL, null, null);
INSERT INTO org VALUES(8, 'Igor', 7, null, null);
INSERT INTO org VALUES(9, 'Jerome', 7, 8, null);

戴夫引用了海伦带领的树。

我添加了 refs 子句：

WITH RECURSIVE
refs(id, name, boss, sibling, ref, lref) AS (
 SELECT id, name, boss, sibling, ref, 0 FROM org
UNION ALL
 SELECT org.id, org.name, org.boss, org.sibling, org.ref, refs.lref+1
 FROM org JOIN refs ON org.id=refs.ref
),
sibs(id, name, boss, lref, lsib) AS (
 SELECT id, name, boss, lref, 0 FROM refs
 WHERE sibling IS NULL
UNION ALL
 SELECT refs.id, refs.name, refs.boss, refs.lref, sibs.lsib + 1
 FROM refs
 JOIN sibs ON refs.boss = sibs.boss
 AND refs.sibling = sibs.id
),
tree(id, name, lsib, lref, level) AS (
 select id, name, 0, 0, 0 from org where id = 0
UNION ALL
 SELECT sibs.id, sibs.name, sibs.lsib, sibs.lref, tree.level+1
 FROM sibs JOIN tree ON sibs.boss=tree.id
ORDER BY 4 DESC, 5 DESC, 3 DESC
)
SELECT group_concat(name) FROM tree;

但结果不包括海伦的树：

爱丽丝、辛迪、盖尔、弗雷德、鲍勃、戴夫、艾玛

如何使用 Helen 的树获得完整的结果：

爱丽丝、辛迪、盖尔、弗雷德、鲍勃、戴夫、海伦、伊戈尔、杰罗姆、艾玛

编辑 ：

Bob 和 Cindy - 以及 Fred&Gail- 被颠倒了......实际的预期结果是：

爱丽丝、鲍勃、戴夫、海伦、伊戈尔、杰罗姆、艾玛、辛迪、弗雷德、盖尔

标签： sqlsqlitecommon-table-expression

解决方案

这将起作用：

SELECT LISTAGG(name, ', ') WITHIN GROUP (ORDER BY name)
      FROM org
      START WITH boss is null 
      CONNECT BY PRIOR id= boss
      ORDER SIBLINGS BY sibling;

所需输出：

Alice, Bob, Cindy, Dave, Emma, Fred, Gail, Helen, Igor, Jerome

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