请教大神关于SQL排序的问题

Question

SQL_NO.1:select *
  from (select t2.user_id   userId, 
                   t2.user_name userName, 
                   t1.full_name orgFullName, 
                   t2.sort_num, 
                   t2.py_name, 
                   t2.org_id 
          from ((select * 
                   from t_sm_user t 
                  where t.org_id in (select org_id 
                                       from t_md_orgnization t 
                                       where level_num like '%12062%' ) 
                  order by t.sort_num, 
                              nlssort(t.py_name,'NLS_SORT=SCHINESE_PINYIN_M')) t2 left join 
                t_md_orgnization t1 on t2.org_id = t1.org_id))                
SQL_NO.2:select *
  from (select t2.user_id   userId,
                   t2.user_name userName,
                   t1.full_name orgFullNam
         from ((select *
                   from t_sm_user t
                  where t.org_id in (select org_id
                                       from t_md_orgnization t
                                       where level_num like '%12062%' )
                  order by t.sort_num,
                          nlssort(t.py_name,'NLS_SORT=SCHINESE_PINYIN_M')) t2 left join
                t_md_orgnization t1 on t2.org_id = t1.org_id))      
 where rownum <= 20请教大神，这两条SQL语句的区别。  为什么执行后的排序不一样？

Answer 1

在排序之前 你先看看 两句sql查询出的结果是不是一致的