分页查找总结

select * from (select e.*,rownum rn from (select * from emp) e) a1 where a1.rn > 6 and a1.rn  < 10; 

    select * from (select a1.*,rownum rn from(select * from emp) a1 where rownum<=10) where rn>=6; 

select * from (select e.*,rownum rn from emp e) a1 where a1.rn between 6 and 10; 

    /**
         * Oracle 分页sql语句生成方法
         * @param sql sql语句
         * @param pageIndex 页下标
         * @param pageSize 页面大小
         * @return
         */ 
       public  static String createOraclePagingSql(String sql, int pageIndex, int pageSize){ 
           int m = (pageIndex-1) * pageSize;  
           int n = m + pageSize;  
           StringBuffer pagingSelect = new StringBuffer(100);  
           pagingSelect.append("select * from ( select row_.*, rownum rownum_ from ( ") 
           .append(sql)  
           .append(" ) row_ where rownum <=") 
           .append(n) 
           .append(") where rownum_ >") 
           .append(n);      
           return pagingSelect.toString();   
       } 



MySql分页查找
select * from dept order by deptno limit 4, 1;
表示从表dept的第四行 开始数后面的一条；

select * from dept order by deptno desc limit 4, 2;
表示从表dept的第四行开始，查找前面的两行；

在HQL中分页查找：
Query q = session.createQuery ( "from Category c order by c.name desc");
q.setMaxResult(4); 最多显示四条
q.setFirstResult(2); 设置从第二条开始