在T-SQL中，我会这样做:

WITH TOPTEN AS (
    SELECT *, ROW_NUMBER() 
    over (
        PARTITION BY [group_by_field] 
        order by [prioritise_field]
    ) AS RowNo 
    FROM [table_name]
)
SELECT * FROM TOPTEN WHERE RowNo <= 10

UNION操作符对您有用吗?每个部分有一个SELECT，然后将它们联合在一起。不过，我猜它只适用于固定数量的部分。

您可以尝试这种方法。 这个查询为每个国家返回10个人口最多的城市。

   SELECT city, country, population
   FROM
   (SELECT city, country, population, 
   @country_rank := IF(@current_country = country, @country_rank + 1, 1) AS country_rank,
   @current_country := country 
   FROM cities
   ORDER BY country, population DESC
   ) ranked
   WHERE country_rank <= 10;

这适用于SQL Server 2005(编辑以反映您的澄清):

select *
from Things t
where t.ThingID in (
    select top 10 ThingID
    from Things tt
    where tt.Section = t.Section and tt.ThingDate = @Date
    order by tt.DateEntered desc
    )
    and t.ThingDate = @Date
order by Section, DateEntered desc

SELECT r.*
FROM
(
    SELECT
        r.*,
        ROW_NUMBER() OVER(PARTITION BY r.[SectionID]
                          ORDER BY r.[DateEntered] DESC) rn
    FROM [Records] r
) r
WHERE r.rn <= 10
ORDER BY r.[DateEntered] DESC

如果你知道这些部分是什么，你可以这样做:

select top 10 * from table where section=1
union
select top 10 * from table where section=2
union
select top 10 * from table where section=3