oracle的分页

之前学习oracle时，写的一个分页语句，是对emp表做的分页，为了加深记忆以及方便以后的查询使用，现将语句记录如下：

public List<Emp> queryEmpAllOnRownum(int pageNum) {String sql = "select em.*  from " +"(select rownum rn,e.* from (select * from emp order by deptno) e "+"where rownum <= ?) em where em.rn>= ?";//获取记录的总条数int countRow = new EmpServiceImpl().queryCountEmp();//此处需要重新创建对象调用，否则会出现无效的列类型int pages=(int)(Math.ceil(countRow*1.0/pageSize));//总页数//如果当前页小于第一页，就为第一页if(pageNum<1){pageNum =1;System.out.println("页数不能小于第一页");}//如果当前页大于最后一页，就为最后一页if(pageNum>pages){pageNum =pages;System.out.println("页数不能大于最大页，最大页为："+pages);}int start = (pageNum-1)*pageSize+1;int end = pageNum!=pages?(start+pageSize-1):countRow;String[] params ={end+"",start+""};List<Emp> list = new ArrayList<Emp>();try {this.open(sql);this.exeSelect(params);while(rs.next()){Integer empno = rs.getInt("empno");String ename = rs.getString("ename");String job = rs.getString("job");Integer mgr = rs.getInt("mgr");Date hiredate = rs.getDate("hiredate");Double sal = rs.getDouble("sal");Double comm = rs.getDouble("comm");Integer deptno = rs.getInt("deptno");Emp emp = new Emp(empno,ename,job,mgr,hiredate,sal,comm,deptno);list.add(emp);}} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally{this.close();}return list;}//获取记录的总条数public int queryCountEmp() {String sql = "select count(*) from emp";int i=0;try { this.open(sql);  rs = this.exeSelect(null);while(rs.next()){i = rs.getInt(1);}} catch (ClassNotFoundException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}finally{this.close();}return i;}

比较简单的一个分页语句，有别的去求也可以通过这个语句去变形去添加！