expression动态构成

http://blog.csdn.net/tastelife/article/details/7340205

http://blog.csdn.net/tastelife/article/details/7333513

http://www.cnblogs.com/lyj/archive/2008/03/25/1122157.html

http://msdn.microsoft.com/en-us/library/bb344570(v=vs.110).aspx

http://www.niwozhi.net/demo_c73_i9628.html

http://blogs.msdn.com/b/marcinon/archive/2010/01/14/building-custom-linq-expressions-made-easy-with-dynamicqueryable_2e00_.aspx?Redirected=true