http://www.itpub.net/SQL问题- ITPUB论坛http://www.google.com/search?hl=zh-CN&q=SQL%E9%97%AE%E9%A2%98%E7%9A%84%E8%AE%BA%E5%9D%9B&btnG=Google+%E6%90%9C%E7%B4%A2&lr=