Sql Server - 从组中获取第一条记录

Question

我有一张这样的表

我尝试使用下面的代码来获取＃34; AdID＆＃34;小组

;with cte as
(
  select
    ADID,
    PhotoName,
    PhotoPath,
    rank() over(partition by AdID order by PhotoName) as rn
  from AdPhoto
)  
select ADID,
    PhotoName,
    PhotoPath
from cte
where rn = 1

但结果是这样的输出

AD1001  temptemp_1.jpeg ~/UserUploads/temptemp/
AD1002  temptemp_10.jpg ~/UserUploads/temptemp/

我想要这样的输出

AD1001  temptemp_1.jpeg ~/UserUploads/temptemp/
AD1002  temptemp_5.jpg  ~/UserUploads/temptemp/

请帮忙

Answer 1

请尝试使用order by ID代替order by PhotoName：

;with cte as
(
  select
    ADID,
    PhotoName,
    PhotoPath,
    rank() over(partition by AdID order by ID) as rn
  from AdPhoto
)  
select ADID,
    PhotoName,
    PhotoPath
from cte
where rn = 1

Answer 2

这将有助于这组特定的数据：

;with cte as
(
  select
    ADID,
    PhotoName,
    PhotoPath,
    rank() over(partition by AdID order by len(PhotoName) asc, PhotoName) as rn
  from AdPhoto
)  
select ADID,
    PhotoName,
    PhotoPath
from cte
where rn = 1

但是我建议要么改变光子命名的命名方案，要么找一些其他的排序算法。