层次结构查询，它提供多行输出，希望输出一行

Posted 2021-04-07

我有一个分层表，我获取分层数据但它的行如下所示：表结构：

id      parent_type parent_id    
    71123   FSE         67114       
    67114   DST         67111          
    67111   null            0    

层次结构的输出：

id      parent_type parent_id   level   SYS_CONNECT_BY_PATH(parent_type, '->') 
71123   FSE         67114       1      ->FSE
67114   DST         67111       2      ->FSE->DST
67111   null            0       3      ->FSE->DST->

I WANT RESULT OF ABOVE OUTPUT AS SHOWN BELOW:
id   parent_type parent_id   id   parent_type parent_id  id    parent_type parent_id   
71123   FSE      67114       67114 DST        67111      67111 NULL  0

答案

可能看起来太复杂但实际上很容易。

WITH dat
     AS (SELECT 71123 AS id,
                'FSE' AS parent_type,
                67114 AS parent_id
         FROM   DUAL
         UNION
         SELECT 67114 AS id,
                'DST' AS parent_type,
                67111 AS parent_id
         FROM   DUAL
         UNION
         SELECT 67111 AS id,
                NULL AS parent_type,
                0 AS parent_id
         FROM   DUAL)
SELECT MAX (id_level_1) AS id_level_1,
       MAX (parent_type_level_1) AS parent_type_level_1,
       MAX (parent_id_level_1) AS parent_id_level_1,
       MAX (id_level_2) AS id_level_2,
       MAX (parent_type_level_2) AS parent_type_level_2,
       MAX (parent_id_level_2) AS parent_id_level_2,
       MAX (id_level_3) AS id_level_3,
       MAX (parent_type_level_3) AS parent_type_level_3,
       MAX (parent_id_level_3) AS parent_id_level_3,
       MAX (id_level_4) AS id_level_4,
       MAX (parent_type_level_4) AS parent_type_level_4,
       MAX (parent_id_level_4) AS parent_id_level_4,
       MAX (id_level_5) AS id_level_5,
       MAX (parent_type_level_5) AS parent_type_level_5,
       MAX (parent_id_level_5) AS parent_id_level_5
FROM   (SELECT CASE WHEN l = 1 THEN id ELSE NULL END AS id_level_1,
               CASE WHEN l = 1 THEN parent_type ELSE NULL END AS parent_type_level_1,
               CASE WHEN l = 1 THEN parent_id ELSE NULL END AS parent_id_level_1,
               CASE WHEN l = 2 THEN id ELSE NULL END AS id_level_2,
               CASE WHEN l = 2 THEN parent_type ELSE NULL END AS parent_type_level_2,
               CASE WHEN l = 2 THEN parent_id ELSE NULL END AS parent_id_level_2,
               CASE WHEN l = 3 THEN id ELSE NULL END AS id_level_3,
               CASE WHEN l = 3 THEN parent_type ELSE NULL END AS parent_type_level_3,
               CASE WHEN l = 3 THEN parent_id ELSE NULL END AS parent_id_level_3,
               CASE WHEN l = 4 THEN id ELSE NULL END AS id_level_4,
               CASE WHEN l = 4 THEN parent_type ELSE NULL END AS parent_type_level_4,
               CASE WHEN l = 4 THEN parent_id ELSE NULL END AS parent_id_level_4,
               CASE WHEN l = 5 THEN id ELSE NULL END AS id_level_5,
               CASE WHEN l = 5 THEN parent_type ELSE NULL END AS parent_type_level_5,
               CASE WHEN l = 5 THEN parent_id ELSE NULL END AS parent_id_level_5
        FROM   (SELECT id,
                       parent_type,
                       parent_id,
                       LEVEL AS l
                FROM   dat
                START WITH id = 71123
                CONNECT BY PRIOR parent_id = id));

下面是结果ID_LEVEL_1 | PARENT_TYPE_LEVEL_1 | PARENT_ID_LEVEL_1 | ID_LEVEL_2 | PARENT_TYPE_LEVEL_2 | PARENT_ID_LEVEL_2 | ID_LEVEL_3 | PARENT_TYPE_LEVEL_3 | PARENT_ID_LEVEL_3 | ID_LEVEL_4 | PARENT_TYPE_LEVEL_4 | PARENT_ID_LEVEL_4 | ID_LEVEL_5 | PARENT_TYPE_LEVEL_5 | PARENT_ID_LEVEL_5 71123 | FSE | 67114 | 67114 | DST | 67111 | 67111 | | 0 | | | | | |

但要明白，它只适用于您在问题中所述的5个级别。