How do I get around this cyclical reference in EF?
I am using Entity Framework Code First with SQLCE in MVC3 for a blog-like site. I am open to redesigning the structure if required, it would be great to get some help.
The context is set up as:
public class BinarContext : DbContext
{
public DbSet<Member> Members { get; set; }
public DbSet<Post> Posts { get; set; }
public DbSet<Reply> Replies { get; set; }
public BinarContext()
{
this.Configuration.LazyLoadingEnabled = true;
}
开发者_JS百科 protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Member>().HasMany(member => member.Posts)
.WithRequired(post => post.Member)
.HasForeignKey(post => post.MemberID)
.WillCascadeOnDelete();
modelBuilder.Entity<Member>().HasMany(member => member.Replies)
.WithRequired(reply => reply.Member)
.HasForeignKey(reply => reply.MemberID)
.WillCascadeOnDelete();
modelBuilder.Entity<Post>().HasMany(post => post.Replies)
.WithRequired(reply => reply.Post)
.HasForeignKey(reply => reply.PostID)
.WillCascadeOnDelete();
base.OnModelCreating(modelBuilder);
}
}
*Note: * I have tried getting rid of WillCascadeOnDelete();
as suggested by others on SO but hasn't worked so far.
The models are:
The Member class has information about the posts and replies made by the member.
public class Member
{
public Guid ID {get; set;}
public string Username { get; set; }
public string Email { get; set; }
public virtual ICollection<Post> Posts { get; set; }
public virtual ICollection<Reply> Replies { get; set; }
}
The Post class that has information about the member who posted it and for the replied posted for it.
public class Post
{
public Guid ID {get; set;}
[DataType(DataType.MultilineText)]
public string Text { get; set; }
public Guid MemberID { get; set; }
public virtual Member Member { get; set; }
public virtual ICollection<Reply> Replies { get; set; }
}
The Reply class that has information about the member who posted it and for the post it was posted.
public class Reply
{
public Guid ID { get; set; }
[DataType(DataType.MultilineText)]
public string Text { get; set; }
public Guid PostID { get; set; }
public Guid MemberID { get; set; }
public virtual Post Post { get; set; }
public virtual Member Member { get; set; }
}
Thanks for your help :)
Try this:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Member>().HasKey(x=>x.ID)
.HasMany(x => x.Posts)
.WillCascadeOnDelete();
modelBuilder.Entity<Member>().HasKey(x=>x.ID)
.HasMany(x => x.Replies)
.WillCascadeOnDelete();
modelBuilder.Entity<Post>().HasKey(x=>x.ID)
.HasMany(x => x.Replies)
.WillCascadeOnDelete();
modelBuilder.Entity<Post>().HasKey(x=>x.ID)
.WithRequired(x => x.Member)
.WithMany(x=>x.Posts);
modelBuilder.Entity<Replies>().HasKey(x=>x.ID)
.WithRequired(x => x.Member)
.WithMany(x=>x.Replies);
modelBuilder.Entity<Replies>().HasKey(x=>x.ID)
.WithRequired(x => x.Post)
.WithMany(x=>x.Replies);
base.OnModelCreating(modelBuilder);
}
精彩评论