SQL (postgres) - child 的所有 parents 的递归视图

Question

已解决以下：

我有两个表：community2collection(collection_id,community_id) 和 community2community(child_comm_id,parent_comm_id)。

我正在尝试创建一个递归视图，对于任何给定的集合 (collection_id) 将 return 直接社区列表 parent (community_id) ，以及直接社区的任何祖先（因此递归地通过 community2community.

我有

CREATE VIEW hierarchical_comcoltree
AS
    WITH RECURSIVE comcoltree AS
      (SELECT collection_id,
              community_id AS any_community_id
       FROM community2collection
       UNION ALL SELECT com2col.collection_id,
                        com2com.parent_comm_id AS any_community_id
       FROM community2collection com2col
       INNER JOIN community2community com2com
       ON com2com.child_comm_id = com2col.community_id)
    SELECT * FROM comcoltree;

但这只检索直接社区，以及它的第一个 parent，而不是进一步的祖先，查询

SELECT collection_id,
       any_community_id
FROM hierarchical_comcoltree
WHERE collection_id = '13081d45-dcdc-4e4d-94a5-33056c9f0c49'
ORDER BY collection_id ASC;

任何帮助将不胜感激，尝试了一些变体（以及一个函数），但还没有找到一个可行的...

测试数据

community2collection

collection_id	community_id
13081d45-dcdc-4e4d-94a5-33056c9f0c49	17475c16-a03e-4f5f-8928-bef6a4813978
cbc98392-ba86-4ed3-b477-5a4a7652f3f0	88aa4abd-d024-47d2-a1a4-bdb3d744dd24

community2community

child_comm_id	parent_comm_id
17475c16-a03e-4f5f-8928-bef6a4813978	ae12f497-b7de-4cb6-939f-70968a5e7b0a
ae12f497-b7de-4cb6-939f-70968a5e7b0a	05810e9b-cf09-4c13-a750-297cca5fd84f
88aa4abd-d024-47d2-a1a4-bdb3d744dd24	726a8531-4441-4feb-a8fc-b089445bc39e
726a8531-4441-4feb-a8fc-b089445bc39e	ae12f497-b7de-4cb6-939f-70968a5e7b0a
ae12f497-b7de-4cb6-939f-70968a5e7b0a	05810e9b-cf09-4c13-a750-297cca5fd84f

第一次收集的预期结果视图 '13081d45-dcdc-4e4d-94a5-33056c9f0c49'

=> '17475c16-a03e-4f5f-8928-bef6a4813978'、'ae12f497-b7de-4cb6-939f-70968a5e7b0a' 和 '05810e9b-cf09-4c13-a750-297cca5fd84f'

=> 缺少当前解决方案的最后一个

第二次收集的预期结果视图 'cbc98392-ba86-4ed3-b477-5a4a7652f3f0'

=> '88aa4abd-d024-47d2-a1a4-bdb3d744dd24'、'726a8531-4441-4feb-a8fc-b089445bc39e'、'ae12f497-b7de-4cb6-939f-70968a5e7b0a' 和 '05810e9b-cf09-4c13-a750-297cca5fd84f'

=> 缺少当前解决方案的最后两个

测试：

WITH RECURSIVE comcoltree AS
  (SELECT collection_id,
          community_id AS any_community_id
   FROM community2collection
   UNION ALL SELECT com2col.collection_id,
                    com2com.parent_comm_id AS any_community_id
   FROM community2collection com2col
   INNER JOIN community2community com2com ON com2com.child_comm_id = com2col.community_id)
SELECT collection_id,
       any_community_id
FROM comcoltree
WHERE any_community_id = 'cbc98392-ba86-4ed3-b477-5a4a7652f3f0'
ORDER BY collection_id ASC;

Answer 1

您的主要问题是您没有加入递归 CTE (comcoltree)。因此，您永远不会向带有 UNION 的结果集添加任何内容。这是我提供的最好的信息：

WITH RECURSIVE comcoltree AS
(
    SELECT collection_id
         , community_id     AS any_community_id
      FROM community2collection
     WHERE collection_id = 'cbc98392-ba86-4ed3-b477-5a4a7652f3f0'
     UNION ALL
    SELECT prev.collection_id
         , next.parent_comm_id AS any_community_id
      FROM comcoltree prev
      JOIN community2community next ON prev.any_community_id = next.child_comm_id
)
SELECT DISTINCT 
       collection_id
     , any_community_id
  FROM comcoltree
;

Here 是一个 DBFiddle 来展示它的工作原理。我把 distinct 放在那里是因为结果集中有重复项，但我认为这是因为样本数据中有重复项。

ae12f497-b7de-4cb6-939f-70968a5e7b0a 05810e9b-cf09-4c13-a750-297cca5fd84f

SQL (postgres) - child 的所有 parents 的递归视图

SQL (postgres) - Recursive view for all parents of a child

sql

postgresql

view

recursive-query