Question

我在这里发现了一个类似的问题：Move duplicate values to another column，但我不确定这对我有用。

以下是数据的设置方式：

Account_ID  Phone Number  Phone Number ID
1           1             1
1           2             2
1           3             3
1           4             4
1           5             5
1           6             6
2           1             1
2           2             2
2           3             3
2           4             4
2           5             5
2           6             6

每个帐户ID为6个电话号码中的每一个都有一个条目。我希望它看起来像这样：

Account_ID  Phone Number 1  Phone Number 2  Phone Number 3  etc.
1           1               2               3
2           2               2               2

我尝试过这样的CASE语句：

SELECT
Account_ID,
CASE Phone Number ID
WHEN 1 THEN Phone Number END AS "Phone Number 1"
CASE Phone Number ID
WHEN 2 THEN Phone Number END AS "Phone Number 1"
etc.…
GROUP BY 
Case CASE Phone Number ID
WHEN 1 THEN Phone Number END
etc.…

但是，对于每个Account_ID，它仍然没有正确地将数据合并到一行。它将与电话号码ID对应的电话号码放在正确的列中，但每个Account_ID仍然是它自己的行。

有什么想法？我上面提供的链接对于这么多字段来说太嵌套，缓慢和笨拙。无论如何我编写了一个版本来测试它，但它已经运行了15分钟。

提前致谢！

Answer 1

您可以使用 PIVOT 来获取所需的输出。


select * from 
(table1 
   pivot (max("Phone Number") for "Phone Number ID"
  in ('1' as "Phone Number 1",
      '2' as "Phone Number 2",
      '3' as "Phone Number 3",
      '4' as "Phone Number 4",
      '5' as "Phone Number 5",
      '6' as "Phone Number 6"))
 )

<强> SQL FIDDLE DEMO

Answer 2

你很亲密。您需要case和max以及group by：

select Account_ID,
       max(CASE Phone Number ID = 1 then Phone Number end) as "Phone Number 1",
       max(CASE Phone Number ID = 2 then Phone Number end) as "Phone Number 2",
       max(CASE Phone Number ID = 3 then Phone Number end) as "Phone Number 3",
       . . .
from . . .
group by Account_Id

Answer 3

你可以用一堆连接来做到这一点

WITH accounts 
     AS (SELECT DISTINCT account_id 
         FROM   phones) 
SELECT a.account_id, 
       one.phone_number   phone_number_1, 
       two.phone_number   phone_number_2, 
       three.phone_number phone_number_3, 
       four.phone_number  phone_number_4, 
       five.phone_number  phone_number_5, 
       six.phone_number   phone_number_6 
FROM   accounts a 
       LEFT JOIN phones one 
              ON a.account_id = one.account_id 
                 AND one.phone_number_id = 1 
       LEFT JOIN phones two 
              ON two.account_id = two.account_id 
                 AND two.phone_number_id = 2 
       LEFT JOIN phones three 
              ON a.account_id = three.account_id 
                 AND three.phone_number_id = 3 
       LEFT JOIN phones four 
              ON a.account_id = four.account_id 
                 AND four.phone_number_id = 4 
       LEFT JOIN phones five 
              ON a.account_id = five.account_id 
                 AND five.phone_number_id = 5 
       LEFT JOIN phones six 
              ON a.account_id = six.account_id 
                 AND six.phone_number_id = 6

DEMO

将重复值移动到唯一列中

3 个答案: