sql - 如何根据条件选择每组的第一行

Question

我有一个名为DealOffers:的表

I want to select only one record from each group of dealIds where Price is minimum.

即:预期输出应该是这样的:

Answer 1

你可以做这样的事情。但是，如果您最终必须大规模执行此操作，则应该考虑性能。

select *
from (
    select *,
        SeqNum = row_number() over(
            partition by DealId
            order by Price)
    from DealOffers) do
where do.SeqNum = 1;