出错：
The Entity Framework provider type \'System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089\' for the \'System.Data.SqlClient\' ADO.NET provider could not be loaded. Make sure the provider assembly is available to the running application.
See http://go.microsoft.com/fwlink/?LinkId=260882 for more information..
找了好几个小时
找到这篇文章
http://stackoverflow.com/questions/14033193/entity-framework-provider-type-could-not-be-loaded
在EF上下文中添加
public void FixEfProviderServicesProblem()
{
var instance = System.Data.Entity.SqlServer.SqlProviderServices.Instance;
}