1 to many relation to itself in ef5?

Question

I have these classes:

public class ContentType
{
    public int ContentTypeId{get;set;}
    public string Name{get;set;}
    public int Lang{get;set;}
    public bool IsPublished{get;set;}
    public int? ParentId { get; set; }
    public int UserId { get; set; }
    public virtual User User { get; set; }
}

public class Context : DbContext
{
public Context()
{
    base.Configuration.LazyLoadingEnabled = false;
    base.Configuration.ProxyCreationEnabled = false;
    base.Configuration.ValidateOnSaveEnabled = false;
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    base.OnModelCreating(modelBuilder);
    modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
}
public DbSet<ContentType> ContentTypes { get; set; }
}

Now every contenttype has a parent and a list of childrens. How to define this in the model and Context with ef5?

Answer 1

if you want your contenttype class to have children use this code:

public class ContentType
{
     ///other properties
     public ContentType Parent { get; set; }
     public int? ParentId { get; set; }
     public ICollection<ContentType> Childern { get; set; }
}

and map that like this:

 protected override void OnModelCreating(DbModelBuilder modelBuilder)
 {
      modelBuilder.Entity<ContentType>()
            .HasMany(c => c.Children)
            .WithOptional(c => c.Parent)
            .HasForeignKey(c => c.ParentId);

    base.OnModelCreating(modelBuilder);

 }

there you go..

Answer 2

Your Parent and Content Type Table (1 - many (*))

public class Parent
    {
        public int Id { get; set; }
        //other properties in parent class....
        public virtual ICollection<ContentType> ContentTypes  { get; set; }
    }

    public class ContentType
    {
        public int Id { get; set; }
        //other properties...
        public int ParentId { get; set; }//..this will help us to define the relationship in fluent API
        public Parent Parent { get; set; }
    }

In your DBContext Class..

public DbSet<Parent> Parents { get; set; }
public DbSet<ContentType> ContentTypes { get; set; }

protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
        modelBuilder.Entity<ContentType>().HasRequired(c => c.Parent).WithMany(p =>p.ContentTypes).HasForeignKey(c => c.ParentId);
    }

In the same way you can have ContentType class acting as parent with a list of children. You can also check out this link .I hope it helps now. :)

Answer 3

I assume you the children and parent are of type ContentType?

If so, in the base class ContentType add properties:

    public virtual ICollection<ContentType> Children {get;set;}
    public virtual Content Type Parent {get;set;}

Then map the links via for example the modelBuilder [ ref: http://msdn.microsoft.com/en-us/data/jj591620.aspx ] or via EntityTypeConfiguration [ ref: http://msdn.microsoft.com/en-us/library/gg696117(v=vs.113).aspx ]

Basically it's the same as any other relation you would do.