通过查找最大值来填充列

Question

以下是我的一个子查询的输出。我陷入了困境。

ID         | Principal  | Price     |  Difference
102522     | 47000      | 99.9285   |
102522     | 47000      | 100.6801  |  
102522     | 47000      | 99.9285   |  
102522     | 47000      | 100.6801  |  
102522     | 47000      | 99.9285   |  
102522     | 47000      | 100.6801  |  
1048798    | 280000     | 102.3823  |  
1048798    | 280000     | 102.3666  |
1048798    | 280000     | 102.3823  |
1048798    | 280000     | 102.3666  |
1048798    | 280000     | 102.3823  |
1048798    | 280000     | 102.3666  |
1048798    | 280000     | 102.7026  |

我想填充列差异。

应该是给定ID的MAX价格与特定ID的价格之间的差异。

例如。

ID         | Principal  | Price     |  Difference
102522     | 47000      | 99.9285   |  100.6801 - 99.9285
102522     | 47000      | 100.6801  |  100.6801 - 100.6801
102522     | 47000      | 99.9285   |  100.6801 - 99.9285
102522     | 47000      | 100.6801  |  100.6801 - 100.6801
102522     | 47000      | 99.9285   |  100.6801 - 99.9285
102522     | 47000      | 100.6801  |  100.6801 - 100.6801
1048798    | 280000     | 102.3823  |  
1048798    | 280000     | 102.3666  |
1048798    | 280000     | 102.3823  |
1048798    | 280000     | 102.3666  |
1048798    | 280000     | 102.3823  |
1048798    | 280000     | 102.3666  |
1048798    | 280000     | 102.7026  |

我会理解如何进行的任何指示？

Answer 1

你想要的是最大化的窗口功能。 MAX(Price) OVER (PARTITION BY ID)会为您提供每行每个ID的最高价格，然后您只需减去该行的价格，因此您的对帐单就是这样的

Select ID, Pricipal, Price, MAX(Price) OVER (PARTITION BY ID) - Price AS Difference
FROM (subquery)

Answer 2

只需使用窗口功能：

select t.*,
       (max(t.price) over (partition by t.id) - t.price) as difference
from t;