是否可以根据 T-SQL 中另一个 window 函数的结果对数据集进行排名？

Question

有什么方法可以根据另一个 window 函数的结果对数据集进行排名吗？

例如，我有一个类似下面的查询：

select distinct 
    country,
    cast(sum(Sessions) over (partition by country) as float) / cast(sum(sessions) over() as float) as sess_prcnt
from 
    GoogleAnalytics.dbo.SiteVisitsLog
order by 
    sess_prcnt desc

我想做的是按 sess_prcnt 列对国家/地区进行排名。添加像 rank() over(order by sess_prcnt) 这样的行或使用 CTE 会产生错误。

提前致谢！

Answer 1

您说使用 CTE 会产生错误 - 它们会导致什么样的错误？例如，执行

之类的任何问题

; WITH A AS
    (select distinct 
        country,
        cast(sum(Sessions) over (partition by country) as float) / cast(sum(sessions) over() as float) as sess_prcnt
    from 
        GoogleAnalytics.dbo.SiteVisitsLog
    )
SELECT *, rank() OVER (order by sess_prct DESC) AS rnk
FROM A
order by 
    sess_prcnt desc

或类似的使用它作为 FROM 子句的一部分

SELECT *, rank() OVER (order by sess_prct DESC) AS rnk
FROM 
    (select distinct 
        country,
        cast(sum(Sessions) over (partition by country) as float) / cast(sum(sessions) over() as float) as sess_prcnt
    from 
        GoogleAnalytics.dbo.SiteVisitsLog
    ) A
order by 
    sess_prcnt desc

您可能还想确保为您的任务使用适当的排名函数 - ROW_NUMBER, RANK, or DENSE_RANK

是否可以根据 T-SQL 中另一个 window 函数的结果对数据集进行排名？

Is it possible to rank a dataset by the result of another window function in T-SQL?

sql

tsql

sql-server

rank

window-functions