光ADO.NET还是不够. 不同的项目(大/小, 简单/复杂, Web App/Win App, UI/Data/Business在整个项目中比例)就需要不用的解决方案. 就连MICROSOFT它自己还在实践在ADO.NET基础上Persistence layer叫做 Enterprise Library for .NET -- Data Access Application Block
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnpag2/html/entlib.asp
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnpag2/html/entlib.asp