Question

我有下表：

id      purch_d7   purch_d30     
 1         10             25
 2          5             15

我想将其转置/旋转为这种格式

 id     purchase_count   purch_window
  1           10         purch_d7
  1           25         purch_d30 
  2            5         purch_d7
  2           15         purch_d30

我将如何在Vertica中进行此操作？另外，如果想将输出旋转/转置回原始视图，我该怎么做？

Answer 1

您可以尝试使用UNION ALL

SELECT id,purch_d7 as purchase_count,'purch_d7' as purch_window FROM T
UNION ALL 
SELECT id,purch_d30,'purch_d30' FROM T

Answer 2

我想让代码显示我想做的事情。我将垂直旋转命名列到值和“值名称”。因此，我在提供的其他表格中添加了值名称。

在这里：

WITH
-- don't add this first one to your query - it's just your data ...
input(id,purch_d07,purch_d30) AS (
          SELECT  1,10,25
UNION ALL SELECT  2, 5,15
)
,
-- real WITH clause starts here ...
-- add the possible purch types as an in-line table with labels
purch_window(purch_window) AS (
          SELECT 'purch_d07'
UNION ALL SELECT 'purch_d30'
)
SELECT 
  id
, CASE purch_window 
    WHEN 'purch_d07' THEN purch_d07
    WHEN 'purch_d30' THEN purch_d30
  ELSE NULL
  END AS purchase_count
, purch_window
FROM input CROSS JOIN purch_window
ORDER BY 1,3
;

然后向后旋转：...

WITH
input(id,purch_d07,purch_d30) AS (
          SELECT  1,10,25
UNION ALL SELECT  2, 5,15
)
,
-- real WITH clause starts here ...
-- add the possible purch types as an in-line table with labels
purch_window(purch_window) AS (
          SELECT 'purch_d07'
UNION ALL SELECT 'purch_d30'
)
,
pivoted AS (
SELECT 
  id
, CASE purch_window 
    WHEN 'purch_d07' THEN purch_d07
    WHEN 'purch_d30' THEN purch_d30
  ELSE NULL
  END AS purchase_count
, purch_window
FROM input CROSS JOIN purch_window
)
SELECT
  id
, SUM(CASE purch_window WHEN 'purch_d07' THEN purchase_count END) AS purch_d07
, SUM(CASE purch_window WHEN 'purch_d30' THEN purchase_count END) AS purch_d30
FROM pivoted
GROUP BY 1
ORDER BY 1
;

您要做的就是将其复制粘贴到您的vsql客户端（或用于连接Vertica的任何客户端中……）

转换表，使列变成行值

2 个答案: