Sql 如何获取具有相同ID的最新记录？

我想从SQL数据表中获取最新记录。 我有下面的数据表。 但是它返回了0个记录

表1

PKID----FKID-----------CDateTime
1        25     2012-11-19 17:51:22.000
2        25     2012-11-19 17:53:22.000
3        25     2012-11-19 17:54:22.000
4        26     2012-11-19 17:55:22.000
5        26     2012-11-19 17:56:22.000

现在，我想要fkid25的最新记录，它应该返回第三条记录PKID=3 …怎么才能得到呢？ 我已经写了下面的代码，但它没有返回任何内容

SELECT * from Table1 WHERE FKID = 25
 and CDateTime= (select max(CDateTime) From Table1 )

试试这个：

SELECT * from Table1 WHERE FKID = 25
and CDateTime= (select max(CDateTime) From Table1 where FKID = 25)

with cte as(
SELECT *,row_number() over (partition by FKID order by CDateTime desc) as rn 
from Table1 )
select * from cte 
WHERE FKID = 25
and rn=1

---

您的问题是，您正在放置一个永远不会为真的AND约束，因此无法获得任何输出。 这个查询就可以了

 SELECT * from Table1 WHERE FKID = 25
     and CDateTime= (select max(CDateTime) From Table1 where FKID = 25 )

---

您的查询没有返回值，因为子查询从表1中选择maxCDateTime 将为您提供整张表中的最大CDateTime（不适用于FKID=25）

试试这个：

SELECT * from Table1 WHERE FKID = 25
and CDateTime= (select max(CDateTime) From Table1 where FKID = 25)

with cte as(
SELECT *,row_number() over (partition by FKID order by CDateTime desc) as rn 
from Table1 )
select * from cte 
WHERE FKID = 25
and rn=1

---

此问题的另一个解决方案是在子查询上加入自身，该子查询获取每个FKID的最新日期

或者使用公共表表达式

---

TOP1是什么意思？

WITH latestRecords 
AS
(
    SELECT PKID, FKID, CDATETime,
            ROW_NUMBER() OVER (PARTITION BY FKID
                        ORDER BY CDateTime DESC) rn
    FROM TableNAme
)
SELECT PKID, FKID, CDATETime
FROM latestRecords
WHERE rn = 1