No Entity Framework provider found for the ADO.NET provider with invariant name 'System.Data.SqlClient'

运行Web应用程序报错：

No Entity Framework provider found for the ADO.NET provider with invariant name 'System.Data.SqlClient'. Make sure the provider is registered in the 'entityFramework' section of the application config file. See http://go.microsoft.com/fwlink/?LinkId=260882 for more information.

解决方案

• 在Project项目以及Web站点都要安装 EntityFramework！
• Nuget, 安装 EntityFramework和EntityFramework.SqlServer