How can I create ManyToMany relationship between AspNetRoles and Menus table - many-to-many

Question

I am using asp.net mvc identity. I want to create ManyToMany relationship between Roles and Menu table
I found this to create a ManyToMany relationship in EntityFramework between two tables
on
http://www.entityframeworktutorial.net/code-first/configure-many-to-many-relationship-in-code-first.aspx
public class Role
{
public Role() { }
public int RoleId { get; set; }
public string RoleName { get; set; }
public virtual ICollection<Menu> Menus { get; set; }
}
public class Menu
{
public Menu()
{
this.Roles = new HashSet<Role>();
}
public int MenuId { get; set; }
public string MenuName { get; set; }
public virtual ICollection<Role> Roles { get; set; }
}
I am unable to find AspNetRoles Class. My question is how can i create relationship between existing identity tables. ManyToMany, OneToMany and ManyToOne

Answer 1

After some search Here I found my answer
How to implement a relationship between IdentityRole (dbo.AspNetRoles) and a custom entity?
We only have to define this property
public virtual IdentityRole IdentityRole { get; set; }
in role dependent class which will solve the problem.
The reason for not deleting this post is to cover all possible aspects of the questions for this answer

Answer 2

I was trying to follow your solution, based of course on the problem you proposed.
I edited the first code you posted in order to get it working properly. I want to explain the use of the Identities Tables and one proper way to extend or customize them.
Note:
This code will work when using ManyToOne or OneToOne relationships
public virtual IdentityRole IdentityRole { get; set; }
But I wouldn't recommend it, because you will get some weird and unexpected result at some point of your Model Relationships design.
Now I have to say, this was the way it worked for me, I tested a lot and always got what I wanted.
The trick is easy, Always extend your IdentityModel, doesn't matter which one... and then do everything to this model that extended the Original Identity (relationship, referencing, adding properties, ect...).
With all that said, Let's see the sample now:
To get the ManyToMany relationship that you where trying to get, you must extend the IdentityRole class, and then work with it for customization.
I will focus on the ManyToMany relationship example, because I have the feeling is the less common sample out there.
So here we go :
DBContext is the same for both samples:
public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
.
.
.
override
public IDbSet<IdentityRole> Roles { get; set; }
public DbSet<Menu> Menus { get; set; }
}
Entities:
public class Role : IdentityRole
{
public Role() { }
public string RoleName { get; set; }
public virtual ICollection<Menu> Menus { get; set; }
}
public class Menu
{
public Menu()
{
this.Roles = new HashSet<Role>();
}
public int Id{ get; set; }
public string MenuName { get; set; }
public virtual ICollection<Role> Roles { get; set; }
}
Which generates this migration:
CreateTable(
"dbo.Menus",
c => new
{
Id = c.Int(nullable: false, identity: true),
MenuName = c.String(),
})
.PrimaryKey(t => t.Id);
CreateTable(
"dbo.AspNetRoles",
c => new
{
Id = c.String(nullable: false, maxLength: 128),
Name = c.String(nullable: false, maxLength: 256),
RoleName = c.String(),
Discriminator = c.String(nullable: false, maxLength: 128),
})
.PrimaryKey(t => t.Id)
.Index(t => t.Name, unique: true, name: "RoleNameIndex");
CreateTable(
"dbo.RoleMenus",
c => new
{
Role_Id = c.String(nullable: false, maxLength: 128),
Menu_Id = c.Int(nullable: false),
})
.PrimaryKey(t => new { t.Role_Id, t.Menu_Id })
.ForeignKey("dbo.AspNetRoles", t => t.Role_Id, cascadeDelete: true)
.ForeignKey("dbo.Menus", t => t.Menu_Id, cascadeDelete: true)
.Index(t => t.Role_Id)
.Index(t => t.Menu_Id);
As you can see, there is a pivot table that was automatically created RoleMenus and automatically added the respective relationships.
On the other side, if someone follow your example and use the IdentityRole to create a ManyToMany relationship, using the ICollection .
Let's see :
public class Role : IdentityRole
{
public Role() { }
public string RoleName { get; set; }
public virtual ICollection<Menu> Menus { get; set; }
}
public class Menu
{
public Menu()
{
this.Roles = new HashSet<IdentityRole>();
}
public int Id{ get; set; }
public string MenuName { get; set; }
public virtual ICollection<IdentityRole> Roles { get; set; }
}
Generating :
CreateTable(
"dbo.Menus",
c => new
{
Id = c.Int(nullable: false, identity: true),
MenuName = c.String(),
Role_Id = c.String(maxLength: 128),
})
.PrimaryKey(t => t.Id)
.ForeignKey("dbo.AspNetRoles", t => t.Role_Id)
.Index(t => t.Role_Id);
CreateTable(
"dbo.AspNetRoles",
c => new
{
Id = c.String(nullable: false, maxLength: 128),
Name = c.String(nullable: false, maxLength: 256),
RoleName = c.String(),
Discriminator = c.String(nullable: false, maxLength: 128),
Menu_Id = c.Int(),
})
.PrimaryKey(t => t.Id)
.ForeignKey("dbo.Menus", t => t.Menu_Id)
.Index(t => t.Name, unique: true, name: "RoleNameIndex")
.Index(t => t.Menu_Id);
As you can see, the relationship created was a trial of a OneToOne, not the result we were expecting and if we reference the original IdentityModel to do some sort of relationship, we'll always gonna get it wrong at some point.
So I guess this was it, sorry for the long post, but I felt that somebody should have talked about how to edit the IdentityModel or at least in one functional way.
So I hope this helps somebody that run into same necessity in the future.
Sorry for my English.
Regards.