SQL问题:如何在每个记录组中选择任意数量的记录?

select *
from (
    select
        row_number() over (partition by uid order by UpdateDt desc) 
        as rn
    ,   *
    from YourTable
) sub
where rn <= 3

solution with user variables .

DECLARE @Top tinyint;

SELECT @Top = ABS(CHECKSUM(NEWID())) % 5 + 1;

;WITH MyCTE AS
(
    SELECT
        stuff, things, 
        ROW_NUMBER() OVER (PARTITION BY uid ORDER BY UpdatedDateTime DESC) AS Ranking
    FROM
        MyTable
)
SELECT
    stuff, things
FROM
    MyCTE
WHERE
    Ranking <= @Top