SELECT ID FROM MAILS
WHERE ISPUB = 1
AND ISVAIDATE = 1
AND ISSECRET = 0
AND ISCHOOSEPUB = 1 order by id desc 这个查询是15条记录
SELECT ID FROM MAILS
WHERE ISPUB = 1
AND ISVAIDATE = 1
AND ISSECRET = 0
AND ISCHOOSEPUB = 1 and rownum<=10 order by id desc
这个查询出来根本不是按order by的条件来排序的
WHERE ISPUB = 1
AND ISVAIDATE = 1
AND ISSECRET = 0
AND ISCHOOSEPUB = 1 order by id desc 这个查询是15条记录
SELECT ID FROM MAILS
WHERE ISPUB = 1
AND ISVAIDATE = 1
AND ISSECRET = 0
AND ISCHOOSEPUB = 1 and rownum<=10 order by id desc
这个查询出来根本不是按order by的条件来排序的
from (
SELECT ID FROM MAILS
WHERE ISPUB = 1
AND ISVAIDATE = 1
AND ISSECRET = 0
AND ISCHOOSEPUB = 1 order by id desc
)
where rownum <=10
详细请看此贴
http://topic.csdn.net/u/20080827/17/5962849a-6504-4b4b-8d71-fcf9bf7f9664.html
(SELECT ID FROM MAILS
WHERE ISPUB = 1
AND ISVAIDATE = 1
AND ISSECRET = 0
AND ISCHOOSEPUB = 1 order by id desc)
where rownum <=10