I got the following error when I used sqlce 4.0 with entityframework 6.0
No Entity Framework provider found for the ADO.NET provider with invariant name \'Sy
To achieve this you just need to register the EntityFramework.SqlServerCompact in Package Manager Console,
EntityFramework.SqlServerCompact
To do this open power manager console and type below command:
PM> Install-Package EntityFramework.SqlServerCompact