Sql 内置的分析函数不应用于前N行的功能

想知道是否有任何内置的分析函数支持不应用于SQL查询的前n行

示例代码：

;with cte (num, dollar) as
(
    select 1, cast(1.45 as decimal(12,2))
    union all
    select num + 1, cast(dollar + 1.00 as decimal(12,2))
    from cte
    where num < 20
)
select cte.num, cte.dollar
    , avg(cte.dollar) over (order by cte.num ROWS 3 PRECEDING) as ThreeMonthAvg
    , avg(cte.dollar) over (order by cte.num ROWS 6 PRECEDING) as SixMonthAvg
from cte

是否有内置的方法告诉函数跳过应用函数的前“n”行，但不从结果集中过滤该行

---

检查了Microsoft文档，但我自己找不到任何支持或否认这一点的内容。

没有内置方法，但此版本适用于更多情况：

with cte (num, dollar) as (
      select 1, cast(1.45 as decimal(12,2))
      union all
      select num + 1, cast(dollar + 1.00 as decimal(12,2))
      from cte
      where num < 20
     )
select cte.num, cte.dollar,
       (case when count(*) over (order by cte.num ROWS 3 PRECEDING) = 3
             then avg(cte.dollar) over (order by cte.num ROWS 3 PRECEDING)
        end) as ThreeMonthAvg,
       (case when count(*) over (order by cte.num ROWS 6 PRECEDING) = 6
             then avg(cte.dollar) over (order by cte.num ROWS 6 PRECEDING)
        end) as SixMonthAvg
from cte;

这实际上是对进入平均值的行进行计数，而不是取决于特定的数值

with cte (num, dollar) as (
      select 1, cast(1.45 as decimal(12,2))
      union all
      select num + 1, cast(dollar + 1.00 as decimal(12,2))
      from cte
      where num < 20
     )
select cte.num, cte.dollar,
       (case when count(*) over (order by cte.num ROWS 3 PRECEDING) = 3
             then avg(cte.dollar) over (order by cte.num ROWS 3 PRECEDING)
        end) as ThreeMonthAvg,
       (case when count(*) over (order by cte.num ROWS 6 PRECEDING) = 6
             then avg(cte.dollar) over (order by cte.num ROWS 6 PRECEDING)
        end) as SixMonthAvg
from cte;