select * from table as a inner join ( select MAX(dtmcreateDate) as datetimes,lngExposureID from table group by lngExposureID ) as b on a.lngExposureID = b.lngExposureID and a.dtmcreateDate = b.datetimes
思路：根据类型group，取出最新时间数据，在根据联合主键查询出其他列
原文：http://www.cnblogs.com/yhdkzy/p/4998144.html