表中具有特定列总和的行

Question

我有一个表格，其中包含一些看起来像这样的付款：

id  |  from  |  to  |  amount
--------------------------
1   |   125  | 135  |  2.4
2   |   123  | 134  |  1.7
3   |   124  | 138  |  4.8
4   |   118  | 119  |  3.9
5   |   56   | 254  |  23.5
... 

我需要知道是否有一种方法可以进行 SQL 查询，它会告诉我是否有一系列连续的行，其数量总计为某个值。例如，如果我想要值 6.5，它将返回第 2 到第 3 行。如果我想要 12.8，它将返回第 1 到第 4 行，依此类推。

我完全被卡住了，希望能得到一些帮助。

Answer 1

我会这样处理。首先，计算累积和。那么，连续行具有特定和的条件相当于说两个累积和之间的差等于该值。

with p as (
      select p.*, sum(amount) over (order by id) as cumamount
      from payments p
     )
select 
from p p1 join
     p p2
     on p1.id <= p2.id and
       ( p2.cumamount - p1.cumamount ) = 6.5;

注意：如果amount 存储为浮点数，这可能不起作用，因为误差非常小。如果amount 是一个整数，那很好，但显然不是。定点表示应该没问题。

Answer 2

;with numbers as (select number from master..spt_values where type='p' and number between 1 and (Select MAX(id) from yourtable)),
ranges as ( select n1.number as start, n2.number as finish from numbers n1 cross join numbers n2 where n1.number<=n2.number)
    select yourtable.* from yourtable
        inner join
        (
            select start, finish
            from ranges
                inner join yourtable on id between start and finish
            group by start, finish
            having SUM(amount)=12.8 
        ) results
    on yourtable.id between start and finish