oracle 分頁大於等於小於分頁臨界點

正確的：

SELECT * FROM (SELECT A.*,ROWNUM RN FROM ( 
select * from t_agent t where  t.agent_parent = 20020 
and t.agent_state = 0 

) A WHERE ROWNUM <= 22) WHERE RN >  0;

錯誤的：這樣只會取出21條數據，到臨界點，比如有22條數據，下一頁不會顯示一條數據，只會看到一頁，21條數據，少了一條。

SELECT * FROM (SELECT A.*,ROWNUM RN FROM ( 
select * from t_agent t where  t.agent_parent = 20020 
and t.agent_state = 0 

) A WHERE ROWNUM < 22) WHERE RN >=  0;