Sql server 2008 如何使用TSQL获得所需的结果集？

以下是我的表格结构：-

Table01
ID  Name    FkID  dateTime
1   John    1     2012-06-01
2   Peter   2     2012-06-02
3   Penny   2     2012-06-03
4   Patty   3     2012-06-01

我尝试了此查询，但：(

---

我需要FkID的唯一结果，但从重复的FkID中，我需要在最新日期时间提取行。请选择任何指导线。

您可以使用行号来实现这一点

WITH A AS (
  SELECT *, ROW_NUMBER() OVER (PARTITION BY FkID ORDER BY dateTime DESC) AS rn
  FROM Table01 
)
SELECT ID, Name, FkID, dateTime
FROM A
WHERE rn = 1;

---

我使用了一个通用的表表达式（带语句的

），但是你也可以用普通的子查询来实现。但是实际上，
ROW_NUMBER（）
在处理分组数据（或者说分区）时是一件好事。
你可以通过在表上连接两次来实现这一点

select t1.id, t1.name, t1.dt
from t t1
inner join
(
    select fkid, max(dt) as dt
    from t
    group by fkid
) t2
    on t1.fkid = t2.fkid
    and t1.dt = t2.dt
order by t1.id

看

WITH A AS (
  SELECT *, ROW_NUMBER() OVER (PARTITION BY FkID ORDER BY dateTime DESC) AS rn
  FROM Table01 
)
SELECT ID, Name, FkID, dateTime
FROM A
WHERE rn = 1;

select t1.id, t1.name, t1.dt
from t t1
inner join
(
    select fkid, max(dt) as dt
    from t
    group by fkid
) t2
    on t1.fkid = t2.fkid
    and t1.dt = t2.dt
order by t1.id