Q:

ADO.NET EF how to set FK with Code First

I have these classes that describes my DB model:
 public class Blog
    {
        public int BlogId { get; set; }
        public string Name { get; set; }
        public string Url { get; set; }

        public virtual List<Post> Posts { get; set; }
    }

    public class Post
    {
        public int PostId { get; set; }
        public string Title { get; set; }
        public string Content { get; set; }

        public int BlogId { get; set; }
        public virtual Blog Blog { get; set; }
    }

    public class User
    {
        public int UserId { get; set; }
        public string Username { get; set; }
        public string DisplayName { get; set; }
    }

    public class BloggingContext : DbContext
    {
        public DbSet<Blog> Blogs { get; set; }
        public DbSet<Post> Posts { get; set; }
        public DbSet<User> Users { get; set; }
    }

It's working fine, but when I try to add FK constraint in App. Config like this:
  <entityFramework>
    <defaultConnectionFactory type="System. Data. Entity. Infrastructure. SqlConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="System. Data. SqlClient" />
      </parameters>
    </defaultConnectionFactory>
    <Association Name="UserBlogs">
      <End Type="CodeFirstNewDatabaseSample. BloggingContext. User" Role="User" Multiplicity="1" >
        <OnDelete Action="Cascade" />
      </End>
      <End Type="CodeFirstNewDatabaseSample. BloggingContext. Blog" Role="Blog" Multiplicity="*" />
      <ReferentialConstraint>
        <Principal Role="User">
          <PropertyRef Name="UserId" />
        </Principal>
        <Dependent Role="Blog">
          <PropertyRef Name="UserId" />
        </Dependent>
      </ReferentialConstraint>
    </Association>
  </entityFramework>

I get an error that App. Config has threw an error.  How can I add FKeys using this code as a sample and is App. Config the right place to do that? 

A:

The modelbuilder is my preferred method of configuring FKs with Entity Framework
Check out my blog post which goes into the details of how to do this here: http://blog.staticvoid.co.nz/2012/7/17/entity_framework-navigation_property_basics_with_code_first

