Entity Framework 学习初级篇1--EF基本概况
http://www.cnblogs.com/xray2005/archive/2009/05/07/1452033.html
ORM 对象关系映射(Object-Relational Mapping)
http://www.cnblogs.com/n-pei/archive/2011/08/24/2152383.html
http://blog.csdn.net/zxc22436/article/details/6875220