很容易理解的IN和EXISTS区别
摘要：
在ASKTOM的讲解：Well, the two are processed very very differently.Select * from T1 where x in ( select y from T2 )is typically processed as:select * from t1, ( select distinct y from t2 ) t2where t1.x = t2... 阅读全文
posted @ 2009-05-21 16:54 .net学习交流 阅读(293) 评论(0) 推荐(0) 编辑
