SQL: 划分两列

Question

我关注table：

---------------------
| No1 | No2  | Amount
---------------------
| A   |  B   |    10 |
| C   |  D   |    20 |
| B   |  A   |    30 |
| D   |  C   |    40 |
---------------------

我想对两列 (No1,No2) 的分区求和，但是当两列中的值发生变化时它也应该分组。例如：AB = BA

这将是我的预期结果：

-----------------------------------------
| No1 | No2  | Sum(Amount) over partition
-----------------------------------------
| A   |  B   |    40                    |
| C   |  D   |    60                    |
| B   |  A   |    40                    |
| D   |  C   |    60                    |
-----------------------------------------

有什么想法吗？

Answer 1

使用least和greatest。

select no1,no2,sum(amount) over(partition by least(no1,no2),greatest(no1,no2)) as total
from tbl

Answer 2

只是一个想法：

WITH test_data AS
(
SELECT 'A' no1, 'B' no2, 10 amt FROM dual
UNION ALL
SELECT 'C', 'D', 20 FROM dual
UNION ALL
SELECT 'B', 'A', 30 FROM dual
UNION ALL
SELECT 'D', 'C', 40 FROM dual
)
SELECT NVL(no1, break_group) no1, no2, total --, grp1, grp2, break_group 
  FROM
(
SELECT no1, no2, total
     , grouping(no1) grp1
     , grouping(no2) grp2
     , LAG(no1, 2) OVER (PARTITION BY total ORDER BY no1)||LAG(no1) OVER (PARTITION BY total ORDER BY no1) break_group
  FROM
( -- Vamsi Prabhala query --
select no1, no2
     , sum(amt) over(partition by least(no1,no2),greatest(no1,no2)) as total
from test_data
)
GROUP BY ROLLUP (total, no1, no2)
HAVING grouping(no1) + grouping(no2) = 0
OR grouping(no1) + grouping(no2) = 2
AND total IS NOT NULL
)
/

输出 - 您可以用任何 vlue 替换空值（空）：

|NO1 |  NO2  | Total
----------------------
A        B      40
B        A      40
AB              40
C        D      60
D        C      60
CD              60

SQL: 划分两列

SQL: partition over two columns

sql

oracle

window-functions