如何从SQL Server中的聚合方法获取不同的值

Question

我想选择最短和最长的名称，如果有多个相同长度的名称，我应该按名称排序第一个

例如，如果我具有以下值：

'abc', 'def', 'abcd', 'defghi', 'ghi'

我应该得到类似

abc    3
defghi 6

这是我的查询

select 
    Name, LEN(Name)
from 
    Customer
where 
    len(Name) = (select min(len(Name)) from Customer)
    or
    len(Name) = (select max(len(Name)) from Customer)
order by
    Name;

但是这就是我得到的

abc    3
def    3
defghi 6
ghi    3

Answer 1

我认为这是最容易与top union all最简单方法：

select *
from ((select top 1 c.*
       from customer
       order by len(name) desc, name
      ) union all
      (select top 1 c.*
       from customer
       order by len(name) asc, name
      )
     ) t;

Answer 2

具有窗口功能：

with cte as(select *, 
                   row_number() over(order by len(name), name) rn1,
                   row_number() over(order by len(name) desc, name) rn2
            from Customer)
select name, len(name) from cte where rn1 = 1 or rn2 = 1

Answer 3

您可以按长度和名称来订购它们，例如：

declare @data table(name varchar(10))
insert into @data(name) values('abc'), ('def'), ('abcd'), ('defghi'), ('ghi')

Select name From (
    Select *
        , small = ROW_NUMBER() over(order by len(name), name)
        , big = ROW_NUMBER() over(order by len(name) desc, name)
    From @data
) t
Where small = 1 or big = 1