讨论一下orm的效率问题 hibernate,mybatis,jdbc;
三种方式访问数据库,都用com.mchange.v2.c3p0.ComboPooledDataSource这个DataSource,
sql语句(hql就不贴了);select B.ID, A.name,B.subject,A.score from
(select name,max(score) as score from tbA group by tbA.name) a,tbA as b
where b.name=a.name and b.score=a.score
这样查询的结果大约有3万条