Sql 移动平均/滚动平均

我在MS SQL中有两列，一列是序列号，另一列是值。我需要第三列，它给出该行和下一行2的值之和

前

所以我需要第三列，它的和是2+3+1，3+1+2等等，所以第八行和第九行没有任何值：

1   2   6   
2   3   6   
3   1   4   
4   2   5   
5   1   6   
7   2   7   
8   3       
9   2       

这个解决方案是否可以是通用的，这样我就可以改变当前的窗口大小，将3个数字添加到一个更大的数字上，比如60

select one.sno, one.values, one.values+two.values+three.values as thesum
from yourtable as one
left join yourtable as two
on one.sno=two.sno-1
left join yourtable as three
on one.sno=three.sno-2

或者，根据您评论中的要求，您可以这样做：

select sno, sum(values)
over (
    order by sno
    rows between current row and 3 following
)
from yourtable

---

如果

sno

字段不是顺序字段，您可以使用带聚合的

row\u number（）

：

with ss as (
      select sno, values, row_number() over (order by sno) as seqnum
      from s
     )
select s1.sno, s1.values,
       (case when count(s2.values) = 3 then sum(s2.values) end) as avg3
from ss s1 left outer join
     ss s2
     on s2.seqnum between s1.seqnum - 2 and s1.seqnum
group by s1.sno, s1.values;

---

如果您需要一个完全通用的解决方案，您可以在其中求和，例如，当前行+下一行+下一行的第五行：

步骤1：创建一个表，列出所需的偏移量。0=当前行，1=下一行，-1=上一行，依此类推

SELECT * FROM (VALUES
  (0),(1),(2)
) o(offset)

步骤2：在此模板中使用该偏移表（通过CTE或实际表格）：

此外，如果SNo不是顺序的，则可以获取行\ u NUMBER（），并在该行上进行连接

WITH
  o AS (SELECT * FROM (VALUES (0),(1),(2) ) o(offset)),
  t AS (SELECT *,ROW_NUMBER() OVER(ORDER BY sno) i FROM @t)
SELECT
  t1.sno,
  t1.value,
  SUM(t2.Value)
FROM t t1
INNER JOIN t t2 CROSS JOIN o
  ON t2.i = t1.i + o.offset
GROUP BY t1.sno,t1.value
ORDER BY t1.sno

下面是演示以下查询的示例：

WITH TempS as 
(
  SELECT s.SNo, s.value, 
  ROW_NUMBER() OVER (ORDER BY s.SNo) AS RowNumber
  FROM MyTable AS s
)
SELECT m.SNo, m.value,
(
  SELECT SUM(s.value) 
  FROM TempS AS s
  WHERE RowNumber >= m.RowNumber
  AND RowNumber <= m.RowNumber + 2
) AS Sum3InRow
FROM TempS AS m

---

正如您所见，它非常灵活，因为您只需更改一个数字。

可以将此设置为通用设置，因为我必须将窗口大小从3更改为60，并且创建如此多的连接将非常缓慢，而且会消耗资源。此查询无法与提供的示例数据一起工作。样本数据中缺少

SNo

6。因此，对于SNo，它是5，7，8加在一起的。抓到了，留恋。我只是想。。。不过，第二个查询应该可以正常工作。只需要将3修改为所需的数字。嗨，戈登，这是我从你的查询中得到的结果。（贴在上面）。我在上面加了订单。它应该将最后2行保留为空。你能帮忙吗？我们还必须将3和seqnum-2更改为所需的N和seqnum-（N-1），对吗？

WITH
  o AS (SELECT * FROM (VALUES (0),(1),(2) ) o(offset)),
  t AS (SELECT *,ROW_NUMBER() OVER(ORDER BY sno) i FROM @t)
SELECT
  t1.sno,
  t1.value,
  SUM(t2.Value)
FROM t t1
INNER JOIN t t2 CROSS JOIN o
  ON t2.i = t1.i + o.offset
GROUP BY t1.sno,t1.value
ORDER BY t1.sno

WITH TempS as 
(
  SELECT s.SNo, s.value, 
  ROW_NUMBER() OVER (ORDER BY s.SNo) AS RowNumber
  FROM MyTable AS s
)
SELECT m.SNo, m.value,
(
  SELECT SUM(s.value) 
  FROM TempS AS s
  WHERE RowNumber >= m.RowNumber
  AND RowNumber <= m.RowNumber + 2
) AS Sum3InRow
FROM TempS AS m

m.RowNumber + 59