去掉重复，取最大日期的数据，急用在线等，
tab

id cpbh XH sjrq

1 001 A-1 2011-02-09
2 001 A-2 2012-03-07
3 001 A-3 2012-06-20
4 002 B-1 2012-04-15
5 002 B-2 2012-06-01
...


TAB 表有5000多条数据，cpbh 有重复，现在只取最大日期的，结果如下

id cpbh XH sjrq

3 001 A-3 2012-06-20
5 002 B-2 2012-06-01
...

请高手指点，谢谢

[解决办法]
SELECT * FROM TB T WHERE sjrq =(SELECT MAX(sjrq ) FROM TB WHERE cpbh =t.cpbh )
[解决办法]
SELECT *
FROM tab t
where not exists (select 1 from tab where cpbh=t.cpbh and sjrq>t.sjrq)
[解决办法]
很难吗？

SQL code

WITH tab (id, cpbh ,XH ,sjrq  ) AS (SELECT 1, '001', 'A-1' ,'2011-02-09' UNION ALL  SELECT 2 ,'001', 'A-2', '2012-03-07' UNION ALL  SELECT 3 ,'001','A-3', '2012-06-20' UNION ALL  SELECT 4 ,'002', 'B-1', '2012-04-15' UNION ALL  SELECT 5 ,'002', 'B-2', '2012-06-01')  SELECT * FROM TAB a  WHERE EXISTS (SELECT 1 FROM   (SELECT MAX(sjrq) sjrq ,cpbh  FROM TAB  GROUP BY cpbh)b WHERE a.sjrq=b.sjrq AND a.cpbh=b.cpbh)  /*  id          cpbh XH   sjrq ----------- ---- ---- ---------- 3           001  A-3  2012-06-20 5           002  B-2  2012-06-01  (2 行受影响)    */