Oracle sql - 分层查询

Question

我正在努力对以下 table 进行分层查询。

CLASSSTRUCTUREID  PARENT    CLASSIFCATIONID
1688                             FLT
1689              1688           ASSET
1690              1688           PMFLT
1691              1688           CM
1692              1691           POSTFAILCM

例如，对于上面的例子，我想得到如下输出

FLT/CM/POSTFAILCM as FLT is the parent of CM and CM is the parent of POSTFAILCM

我使用了以下查询但没有给我所需的输出。我只是想知道我哪里做错了。

SELECT LPAD(' ', 2*level-1)|| SYS_CONNECT_BY_PATH(CLASSIFICATIONID , '/') "Path"
,LEVEL
   FROM CLASSSTRUCTURE
   START WITH CLASSIFICATIONID = 'PREFAILCM' --TRIED 'FLT' TOO
   CONNECT BY PRIOR  TO_CHAR(CLASSSTRUCTUREUID) = PARENT

Answer 1

希望对您有所帮助：

SELECT    LPAD (' ', 2 * LEVEL - 1) || SYS_CONNECT_BY_PATH (CLASSIFICATIONID, '/') PATH,
           LEVEL
      FROM CLASSSTRUCTURE
START WITH parent IS NULL
CONNECT BY PRIOR TO_CHAR (CLASSSTRUCTUREID) = PARENT;

使用创建 table :

CREATE TABLE CLASSSTRUCTURE AS
(select 1688 CLASSSTRUCTUREID, NULL PARENT,'FLT' CLASSIFICATIONID FROM DUAL UNION ALL
select 1689 CLASSSTRUCTUREID, 1688 ,'ASSET' FROM DUAL UNION ALL
select 1690 CLASSSTRUCTUREID, 1688 ,'PMFLT' FROM DUAL UNION ALL
select 1691 CLASSSTRUCTUREID, 1688 ,'CM' FROM DUAL UNION ALL
select 1692 CLASSSTRUCTUREID, 1691 ,'POSTFAILCM' FROM DUAL );

Oracle sql - 分层查询

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