运行总和整数值分配

Question

我需要能够确定每一行的剩余点分配量。让我解释以下查询：

变量

@allocated int --> 已经分配点数
@to_allocate int --> 我们现在需要分配的点

查看"audits"

ts --> 收集点数的日期
points --> 收集的点数

到目前为止，我只能在 "audits" 中的数据是这样的情况下才能得到正确的结果：

这个有效

IF OBJECT_ID('audits') IS NOT NULL
DROP VIEW audits;

GO

CREATE VIEW audits
AS
SELECT '2000-1-1' AS ts, 10 AS points UNION ALL
SELECT '2000-1-2' AS ts, 12 AS points UNION ALL
SELECT '2000-1-3' AS ts, 123 AS points UNION ALL
SELECT '2000-1-4' AS ts, 100 AS points;

GO

不起作用

CREATE VIEW audits
AS
SELECT '2000-1-1' AS ts, 106 AS points UNION ALL
SELECT '2000-1-2' AS ts, 12 AS points UNION ALL
SELECT '2000-1-3' AS ts, 123 AS points UNION ALL
SELECT '2000-1-4' AS ts, 100 AS points;

GO

查询

DECLARE @to_allocate int = 92;
DECLARE @allocated int = 4;

WITH result
AS
(
    SELECT 
        ts,
        points,
        SUM(points) OVER(ORDER BY ts) AS total
    FROM audits
),
points
AS
(
    SELECT 
        ts,
        points,
        total,
        CASE 
            WHEN @to_allocate > total - @allocated THEN total - @allocated
            ELSE @to_allocate - SUM(total - @allocated) 
                                OVER(ORDER BY ts ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING)
        END as result
    FROM result
)
SELECT * FROM points
WHERE result > 0;

"Does not work" 数据的期望输出

请注意，结果列中的值不应大于相应行的点。因此，

当@to_allocate 为 92

当@to_allocate 为 200

我可以通过使用临时表和循环来解决这个问题，但这是我不想做的事情，因为它阻止我在函数上使用它。任何帮助或指出正确的方向将不胜感激。

Answer 1

是这样的吗？

DECLARE @to_allocate int = 200
DECLARE @allocated int = 4

select *,
  points - 
  case when total < @allocated then points 
       when prev < @allocated then @allocated - prev
       else 0
  end -
  case when total > @to_allocate + @allocated 
       then total - @to_allocate - @allocated 
       else 0 
  end

from
(
  select *, lag(total, 1, 0) over (order by ts asc) as prev
  from
  (
      select *, sum(points) over (order by ts asc) as total from audits
  ) X
) X
where prev < @to_allocate + @allocated

SQL Fiddle

我假设 @allocated 必须从不仅仅是第一行中删除值，尽管你的例子只有那个。

运行总和整数值分配

Running Total and Integer Value Allocation

sql

sql-server

cumulative-sum

运行 总和整数值分配

Running Total and Integer Value Allocation

sql

sql-server

cumulative-sum

运行总和整数值分配