Entity Framework Code First - Sitecore Databases

Question

I want to use entity framework to extend the functionality of Sitecore's membership. As you know, you can't query data efficiently like you can with an SQL database.

I am trying to setup a context class using Code first migrations

public class FilesContext : DbContext
{
    public FilesContext() : base("core")
    {
        Database.CreateIfNotExists();
    }

    public DbSet<File> Files{ get; set; }
}

The problem is that, the Core database doesn't "exist", when I run the Update-Database. However when I call

ConfigurationManager.ConnectionStrings;

I get a list of the connection strings listed in https://doc.sitecore.net/sitecore_experience_platform/81/setting_up_and_maintaining/xdb/configuring_servers/database_connection_strings_for_configuring_servers

and I am wondering why Entity Framework isn't able to pick up the Sitecore databases. I think, maybe when I run the Update-Database command in Package Manager Console, it just tries to invoke a call to the FilesContext class and it doesn't see the bigger picture, which is that the site is running under Sitecore.

Answer 1

I agree with the comments about not using EF CodeFirst approach with any of the default Sitecore databases. I would suggest using a custom database or only using the core database to query data from existing tables (using CodeFirst based on an existing database). Be careful about any changes you make to any of the default Sitecore databases and tables.

That said, when you run the Update-Database command from the Package Manager console you are doing so from the context of Visual Studio and the selected project from the console window. When you are calling ConfigurationManager.ConnectionStrings to get a list of the connection strings I presume you are running this in your website deployed to IIS. EF will not run in the context of the website so does not have access to those.

Assuming you have a separate Class project for your EF project, you need to add the connection string in the App.config of that project and then make sure you build the project since the config will get copied to the /bin folder of that project.

<connectionStrings>
  <add name="core" 
       providerName="System.Data.SqlClient" 
       connectionString="Data Source=(local);Database=Sitecore_core;..." />
</connectionStrings>

You must add the connection string to App.config of the EF project even if it is specified elsewhere (such as in your Web project). Make sure you add the providerName attribute the connection string, you will get an error when using EF without it.