java 取结果集的最后三项，

数据库是oracle 10G

我现在插入数据：

insert into you (id,name) values (1,'john1');

insert into you (id,name) values (2,'john2');

insert into you (id,name) values (3,'john3');

insert into you (id,name) values (4,'john4');

insert into you (id,name) values (5,'john5');

我想取最后三条记录，

3 john3

4 john4

5 john5

这个怎么实现呢？ 请指教

Connection conn = null;
  Statement stmt = null;
  ResultSet rs = null;
  try {
  Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
  conn = DriverManager.getConnection(
  "jdbc:oracle:thin:@localhost:1521:orcl", "zhang",
  "zhang");
  stmt = conn.createStatement();
  String url = "select * from you where rownum<=3 order by id desc";

我这里只能取到前三条，取不了后三条，
  rs = stmt.executeQuery(url);
  while (rs.next()) {
  out.print(rs.getString("id"));
  out.print(rs.getString("name"));
  }
  } catch (Exception e) {
  e.printStackTrace();
  } finally {
  try {
  if (rs != null) {
  rs.close();
  }
  if (stmt != null) {
  stmt.close();
  }
  if (conn != null) {
  conn.close();
  }
  } catch (Exception e) {
  e.printStackTrace();
  }
  }



答案1：
SELECT * FROM  (SELECT * FROM you ORDER BY id DESC ) WHERE ROWNUM<=3;

如果ID是自增的，这样应该是可以的。

答案2：

应该是一个分页查询的问题
select id,name from (select id,name,rownum rn from you where rownum <= (select count(*) from you)) where rn > (select count(*) from you)-3;
最后 -3 是取数据表的最后3条，-n就是取最后几条