hibernate的问题
各位老大，我测了一下hibernate和直接用jdbc取mysql的数据
目的是：从表的10000条记录处取100条，看时间
1.用jdbc取数据
Class.forName("org.gjt.mm.mysql.Driver");
String url="jdbc:mysql://10.0.18.93/test";
String user = "root";
String password = "hello";
Connection conn = DriverManager.getConnection(url, user, password);
Statement stmt = conn.createStatement();
long begintime=System.currentTimeMillis();
ResultSet rs = stmt.executeQuery("select * from post limit 10000,100");
long endtime=System.currentTimeMillis();
System.out.println("query cost time="+(endtime-begintime));
结果：query cost time=235
2.用hibernate
sql = "select post from my.test.Post as post ";
long begintime = System.currentTimeMillis();
System.out.println("Begin time is " + begintime);
query = session.createQuery(sql);
query.setFirstResult(10000);
query.setMaxResults(100);
List catList = query.list();
long middletime = System.currentTimeMillis();
System.out.println("Query cost time is " +
(middletime - begintime));
结果：Query cost time is 8391
使用hibernate的全部代码
public class HibernateMain {
private static SessionFactory sessionFactory;
private static Session session;
private static Transaction transaction;
public static void main(String[] args) {
HibernateMain hm = new HibernateMain();
try {
hm.initHibernate();
session = sessionFactory.openSession();
//取出贴子条数
String sql = "select count(*) from com.alibaba.bizclub.dbo.Post as post ";
Query query = session.createQuery(sql);
Integer count = (Integer) query.iterate().next();
//取出贴子内容
sql = "select post from my.test.Post as post ";
long begintime = System.currentTimeMillis();
System.out.println("Begin time is " + begintime);
query = session.createQuery(sql);
query.setFirstResult(10000);
query.setMaxResults(100);
List catList = query.list();
long middletime = System.currentTimeMillis();
System.out.println("Query cost time is " +
(middletime - begintime));
for (Iterator it = catList.iterator(); it.hasNext();) {
Post post = (Post) it.next();
}
long endtime = System.currentTimeMillis();
System.out.println("End cost time is " + (endtime - begintime));
} catch (HibernateException ee) {
ee.printStackTrace();
}
}
private void initHibernate() throws HibernateException {
sessionFactory = new Configuration().configure().buildSessionFactory();
}
}