title: Problem mapping one to many relationship with EF CTP4
body: <p>I am trying to define a one to many relationship between Category and Project (a Category can have one or many Projects, a Project can have one or no Category)</p>
  
  <pre><code>public class Project : Entity {
  
      public virtual string Title { get; set; }
  
      public virtual Guid? CategoryId { get; set; }
      public virtual Category Category { get; set; }
  }
  
  public class Category : Entity {       
      public virtual string Name { get; set; }
      public virtual ICollection&lt;Project&gt; Projects { get; set; }
  }
  </code></pre>
  
  <p>I have defined the following mappings:</p>
  
  <pre><code>            modelBuilder.Entity&lt;Project&gt;()
              .MapSingleType(p =&gt; new {
                  ProjectId = p.Id,
                  p.CategoryId,
                  p.Title,
                  p.Slug,
                  p.ShortDescription,
                  p.Description,
                  p.CreatedOn,
                  p.UpdatedOn
              })
              .ToTable("Projects");
  
          modelBuilder.Entity&lt;Category&gt;()
              .MapSingleType(c =&gt; new {
                  CategoryId = c.Id,
                  c.Name,
                  c.CreatedOn,
                  c.UpdatedOn
              })
              .ToTable("Categories");
  
          // relationships
          modelBuilder.Entity&lt;Project&gt;()
              .HasOptional&lt;Category&gt;(p =&gt; p.Category)
              .WithMany()
              .HasConstraint((p, c) =&gt; p.CategoryId == c.Id);
  </code></pre>
  
  <p>Now although this appears to be working fine, EF is still generating a Categories_Products table (used for many to many associations).</p>
  
  <p>I've disabled the default database initializer yet this table is still being generated. What am I doing wrong?</p>
  
  <p>Thanks
  Ben</p>