CODEWITHSUNDEEP
c#asp.net-mvc-3code-firstentity-framework-4.1
Sanchit Sharma
Sanchit Sharma

Reputation: 1

EF Code First ASP.NET C# Design

I am trying to use EF Code first to create a database but I am not sure how to define the classes for the following relationship so that it is efficient.

We have a User and User has Friends, which in turn is a collection of User, so I was thinking of the following POCO Class

`//Class User
public class User
{
  public Guid UserId{get;set;}
  public string UserName{get;set;}
  public String UserAddress{get;set;}
  // other user properties
}

//Class Friend
public class Friend
{ 
  public Guid FriendId{get;set;} //unique identifier for Friend Table
  public virtual User CurrentUser{get;set;}
  public List<User> lstUserFriends {get;set;} //contains list of all friends that the     user has

}`

Does this look good performance-wise or do you think you can suggest an alternative?

Upvotes: 0

Views: 316

Answers (2)

Ladislav Mrnka
Ladislav Mrnka

Reputation: 364409

You need self referencing many-to-many relation because use can have many friends but also can be friend of many users.

public class User
{
    public Guid UserId { get; set; }
    public string UserName { get; set; }
    public String UserAddress { get; set; }

    [InverseProperty("Friends")]
    public virtual ICollection<User> FriendWith { get; set; }
    [InverseProperty("FriendWith")]
    public virtual ICollection<User> Friends { get; set;} 
}

Or you can omit InverseProperty data annotation and use fluent mapping:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<User>()
                .HasMany(u => u.Friends)
                .WithMany(f => f.FriendWith);
    // I'm not sure but you can also need to add this:
    //          .WillCascadeOnDelete(false);
}

Upvotes: 3

Andrew Cooper
Andrew Cooper

Reputation: 32596

Why not just do

public class User
{
  public Guid UserId{get;set;}
  public string UserName{get;set;}
  public String UserAddress{get;set;}
  public IList<User> Friends{get;set;}
  // other user properties
}

Upvotes: 4

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