将列转换为分层行

Question

我正在尝试将 4 列转换为行，但采用分层结构。

Col1        Col2        Col3              Col4
YP HEVEA    YP HEVEA    OTHER CREDITORS   L1220001 - OTHER CREDITORS
YP HEVEA    YP HEVEA    PREPAYMENTS       A1323004 - PREPAYMENTS OTHERS
YP HEVEA    YP HEVEA    PREPAYMENTS       A2349032 - PREPAYMENTS NEW

我的要求是将其转换为树层次结构中的单个列，如下所示：

LEVEL     COLUMN
1         YP HEVEA
2         YP HEVEA
3A        OTHER CREDITORS
4A        L1220001 - OTHER CREDITORS
3B        PREPAYMENTS
4B        A1323004 - PREPAYMENTS OTHERS
4B        A2349032 - PREPAYMENTS NEW

我添加了一个“LEVEL”列只是为了显示我想要的顺序，但这在输出中不是必需的。我正在尝试使用

UNPIVOT

但不知道如何实现它。

这是测试数据：

SELECT 
'YP HEVEA' Col1,   'YP HEVEA' Col2,   'OTHER CREDITORS' Col3,  'L1220001 - OTHER CREDITORS' Col4
FROM DUAL
UNION
SELECT 
'YP HEVEA' Col1,   'YP HEVEA' Col2,   'PREPAYMENTS' Col3,      'A1323004 - PREPAYMENTS OTHERS' Col4
FROM DUAL
UNION
SELECT 
'YP HEVEA' Col1,   'YP HEVEA' Col2,   'PREPAYMENTS' Col3,       'A2349032 - PREPAYMENTS NEW' Col4
FROM DUAL

Answer 1

使用

UNPIVOT

将数据转换为分层数据结构，然后使用分层查询并使用

ORDER SIBLINGS BY

生成所需的排序：

WITH hierarchy AS (
  SELECT DISTINCT *
  FROM   (SELECT t.*, NULL AS root FROM table_name t)
         UNPIVOT(
         (parent, child) FOR depth IN (
           (root, col1) AS 1,
           (col1, col2) AS 2,
           (col2, col3) AS 3,
           (col3, col4) AS 4
         )
       )
)
SELECT child,
       LEVEL
FROM   hierarchy
START WITH parent IS NULL
CONNECT BY
       PRIOR child = parent
AND    PRIOR depth + 1 = depth
ORDER SIBLINGS BY child

对于样本数据：

CREATE TABLE table_name (col1, col2, col3, col4) AS
SELECT 'YP HEVEA', 'YP HEVEA', 'OTHER CREDITORS',  'L1220001 - OTHER CREDITORS' FROM DUAL UNION ALL
SELECT 'YP HEVEA', 'YP HEVEA', 'PREPAYMENTS', 'A1323004 - PREPAYMENTS OTHERS' FROM DUAL UNION ALL
SELECT 'YP HEVEA', 'YP HEVEA', 'PREPAYMENTS', 'A2349032 - PREPAYMENTS NEW' FROM DUAL;

输出：

孩子	级别
YP橡胶树	1
YP橡胶树	2
其他债权人	3
L1220001 - 其他债权人	4
预付款	3
A1323004 - 预付款其他	4
A2349032 - 预付款新	4

小提琴