求大家写一条SQL语句

[起个名字忒难]

如图所示，我想要得到每一个客户跟进时间最小的那一条记录该如何写SQL语句

我像这样写但是得到的结果不对
*select b.客户,min(b.跟进时间),b.转化时长
from
(select 客户,跟进时间,转化时长 from temp where 更新客户状态 not in('陌生','再次销售')) as b group by b.客户,b.转化时长

[二月十六]

试试这样

;WITH cte AS (
SELECT    客户 ,
                    跟进时间 ,
                    转化时长
          FROM      temp
          WHERE     更新客户状态 NOT IN ( '陌生', '再次销售' )
),cteb AS (
SELECT  b.客户 ,
        MIN(b.跟进时间) AS 跟进时间
FROM    cte AS b
GROUP BY b.客户 
)
SELECT  cte.*
FROM    cteb
        JOIN cte ON cte.客户 = cteb.客户
                    AND cte.跟进时间 = cteb.跟进时间

[吉普赛的歌]

;WITH cte AS (
	SELECT [客户],
			min([跟进时间]) as [最小跟进时间]
	FROM   temp b
	WHERE  [更新客户状态] NOT IN ('陌生', '再次销售')
	GROUP BY b.[客户]
)
SELECT  
	[客户]
	,[最小跟进时间]
	,(SELECT TOP 1 [转化时长] FROM temp a WHERE a.[客户]=b.[客户] and a.[跟进时间]=b.[最小跟进时间]) as [转化时长]
FROM cte b