我想为一列的运行值添加总和，但是如果序列失败，那么我们就不必添加

Question

我有这样的桌子

+----+--------+------+------+
| id | state  | num  | pop  |
+----+--------+------+------+
|  1 | ny     |    1 |  100 |
|  1 | ny     |    2 |  200 |
|  1 | ny     |    3 |  600 |
|  1 | ny     |    6 |  400 |
|  1 | ny     |    7 |  300 |
|  1 | ny     |   14 | 1000 |
|  2 | nj     |    3 |  250 |
+----+--------+------+------+

我想要输出如下

+---+----+----+------+------+
| 1 | ny |  1 |  100 |  900 |
| 1 | ny |  2 |  200 |  900 |
| 1 | ny |  3 |  600 |  900 |
| 1 | ny |  6 |  400 |  700 |
| 1 | ny |  7 |  300 |  700 |
| 1 | ny | 14 | 1000 | 1000 |
| 2 | nj |  3 |  250 |  250 |
+---+----+----+------+------+

因此，如果num列中有一个seq，那么我们必须添加pop列。因此，前3列num列依次有1,2,3，因此我们添加了弹出列100 + 200 + 600并显示为新列。

我尝试了下面的代码，但没有收到想要的输出

select id, state,num, pop,
sum(pop) over (partition by id, state order by num )
from table

Answer 1

如果减去序列，则这些值对于一行中的值将是恒定的。然后您可以使用窗口功能：

select t.*,
       sum(pop) over (partition by state, num - seqnum) as new_population
from (select t.*,
             row_number() over (partition by state order by num) as seqnum
      from t
     ) t;