Relationship 1:N with RU

Question

I have a table of units as below:

public class Unity
{
 public int Id {get;set }
 public string Name{ get; set; }
}

public class UsersRight
{
 public int Id {get;set }        
 public string Name{ get; set; }
 public int Value{ get; set; }
}

Each user can have access to 1 or n units. I’ll have a list of the units' records.

var userRight = new List<UsersRight>;
userRight = _DAL.UserRights(user);

var listUser = new List<Unity>; 

foreach (var item in userRight)
{ 
  listUser.add( new Unity(Name = item.Name, Id = item.Value));
}

What is the most efficient way to do this with EF? I am using ASP.NET Identity.

Answer 1

In your case with a Unidade may have several Usuarios and a Usuario for having several Unidade, characterizes a relationship N:N, which in the case would have to be done with an extra table making the relationship between the two.

Example :

Unit Table

    public class Unity
{
 public int UnityId {get;set }
 public string Name{ get; set; }
}

Usuario Table

    public class UsersRight
{
 public int UsersRightId {get;set }        
 public string Name{ get; set; }
 public int Value{ get; set; }
}

Is and the connection table between the two tables :

    public class UserUnitty
{
     public int UsersRightId {get;set }
     public int UnityId{ get; set; }

     public virtual UsersRight UsersRight{get;set;}
     public virtual Unity Unity{get;set;}

}

Considerations :

• In the Userunity table, the virtual, the modifier virtual is used by EF to do Lazy Loading, which needs to create proxy instances that will be replaced in these virtual properties. In case when you query these classes will not be filled.
• I used the UnityId and UserRightId not to use the DataAnnotations, but if you want to keep like the orignal you can just use the DataAnnotations to specify which table belongs to thatForeingKey.