Creating inheritance users from base asp.net identity user
Asked Answered
G

3

8

I have problem in which i would like to create N, two in the example, user objects (e.g. Customer & Supplier) which all inherent from the asp.net IdentityUser object. These object have very different additional data besides the the data from the IdentityUser. I would like to use the IdentityUser user as this gives me a flexible way of taking care of authentication and authorization.

This example has been very stripped down but should supply sufficient information concerning the not being able to create a concrete user (e.g. Customer of Supplier). It seems i need to use the UserManager object as this also takes care of creating for example the password hash and additional security information.

I get presented the following error:

{"Attaching an entity of type 'Supplier' failed because another entity of the same type already has the same primary key value. This can happen when using the 'Attach' method or setting the state of an entity to 'Unchanged' or 'Modified' if any entities in the graph have conflicting key values. This may be because some entities are new and have not yet received database-generated key values. In this case use the 'Add' method or the 'Added' entity state to track the graph and then set the state of non-new entities to 'Unchanged' or 'Modified' as appropriate."}

Classes which inherent from IdentityUser

 public class Customer : IdentityUser
 {
    public string CustomerProperty { get; set; }
 }

 public class Supplier : IdentityUser
 {
    public string SupplierProperty { get; set; }
 }

Database context class

 public class ApplicationDbContext : IdentityDbContext {

      public ApplicationDbContext() : base("ApplicationDbContext")
      {
         Database.SetInitializer(new ApplicationDbInitializer());
      }

      public DbSet<Customer> CustomerCollection { get; set; }
      public DbSet<Supplier> SupplierCollection { get; set; }
 }

Seeding class which throws the exception

 public class ApplicationDbInitializer : DropCreateDatabaseAlways<ApplicationDbContext>
 {
    protected override void Seed(ApplicationDbContext context)
    {
        var userStore = new UserStore(context);
        var userManager = new UserManager(userStore);


        // Seed customer user which inherents from asp.net IdentityUser 
        var user = userManager.FindByEmail("[email protected]");
        if (user == null)
        {
            user = new User()
            {
                UserName = "[email protected]",
                Email = "[email protected]"
            };

            userManager.Create(user, userPassword);

            var customerUser = new Customer()
            {
                Id = user.Id,
                CustomerProperty = "Additional Info"
            };

            context.Entry(customerUser).State = EntityState.Modified;
            context.SaveChanges();
        }

        // Seed supplier user which inherents from asp.net IdentityUser 
        var user = userManager.FindByEmail("[email protected]");
        if (user == null)
        {
            user = new User()
            {
                UserName = "[email protected]",
                Email = "[email protected]"
            };

            userManager.Create(user, userPassword);

            var supplierUser = new Supplier()
            {
                Id = user.Id,
                IBAN = "212323424342234",
                Relationship = "OK"
            };

            context.Entry(supplierUser).State = EntityState.Modified;
            context.SaveChanges();
        }
    }
}

**** UPDATE ****

The solution below works but i am still struggling with two issues:

  1. I would always like to have one user type (e.g. Customer of Supplier) associated with the IdentityUser. I though about using an interface but this doesn't work.
  2. If i also add the virtual reference towards the IdentityUser on the user types i get an 'Unable to determine the principal end of an association between the types 'ApplicaitonUser' and 'Supplier'. The principal end of this association must be explicitly configured using either the relationship fluent API or data annotations.' exception.

Classes

 public class Customer 
 {
    [Key]
    public int CustomerId { get;set; }
    public string CustomerProperty { get; set; }

    *public virtual User User { get; set; }*

 }

 public class Supplier 
 {
    [Key]
    public int SupplierId { get;set; }
    public string SupplierProperty { get; set; }

    *public virtual User User { get; set; }*
 }

**Class IdentityUser (which works) **

public class User : IdentityUser
{
    public virtual Supplier Supplier { get; set; }
    public virtual Customer Customer { get; set; }
}

**Class IdentityUser (what i would like) **

public class User : IdentityUser
{
    public virtual IConcreteUser ConcreteUser{ get; set; }
}

Database context class

 public class ApplicationDbContext : IdentityDbContext {

      public ApplicationDbContext() : base("ApplicationDbContext")
      {
         Database.SetInitializer(new ApplicationDbInitializer());
      }

      public DbSet<Customer> CustomerCollection { get; set; }
      public DbSet<Supplier> SupplierCollection { get; set; }
 }

**Seeding class **

 public class ApplicationDbInitializer : DropCreateDatabaseAlways<ApplicationDbContext>
 {
protected override void Seed(ApplicationDbContext context)
{
    var userStore = new UserStore(context);
    var userManager = new UserManager(userStore);
    var roleManager = new RoleManager(roleStore);

    var user = userManager.FindByEmail("[email protected]");
    if (user == null)
    {
        user = new ApplicationUser()
        {
            UserName = "[email protected]",
            Email = "[email protected]"
            Customer = new Customer()
            {
                CustomerProperty = "Additional Info"
            }
        };

        userManager.Create(user, userPassword);
        roleManager.AddUserToRole("Customer");
    }

    user = userManager.FindByEmail("[email protected]");
    if (user == null)
    {
        user = new ApplicationUser()
        {
            UserName = "[email protected]",
            Email = "[email protected]",
            Supplier = new Supplier()
            {
                IBAN = "212323424342234",
                Relationship = "OK"
            }
        };

        userManager.Create(user, userPassword);
        roleManager.AddUserToRole("Supplier");
    }
}

}

Geographical answered 21/11, 2014 at 10:20 Comment(16)
I strongly would suggest to fix the broken design. There is zero need to use inheritance on the ASP.NET level. A login user is funddamentally different from the underlying entity in whatever database management or functioanl group you use. I.e. make a simple asp.net user and do not tie ot to your complex model. Keep them separate.Toothpick
Have you tried following the instructions in the error and setting EntityState.Addedd instead of EntityState.Modified?Bartonbartosch
I think the problem lies in the "mixed state": It is neither EntityState.Modified nor EntityState.Added as User is already added, but e.g. Supplier not...Englert
@TomTom: if i keep the user (e.g. Customer & Supplier) how would i know which user logs in? They will all login with credentials from the IdentityUser.Geographical
You tell the user the ID of the internal user. But you do not put the database level inherited user up to the authentication service.Toothpick
@Ben Robinson Setting the EntityState.Addedd does not work and throws an System.Data.Entity.Validation.DbEntityValidationException error.Geographical
@ChrFin Do you have any suggestion for fixing this?Geographical
@Toothpick what you are saying is that you extend the Customer and Supplier with an additional User Id which references the IdentityUser Id - correct? This does not seem very graceful as this will split certain updates (e.g. username, email and additional information per user type like IBAN, relationship and customerproperty) for a user resides in two tables.Geographical
No. If they do not have an ID field you have a problem already. What I say is KEEP ASP.NET AND YOUR SYSTEM SEPARATE. Noone needs IBAN in ASP.NET identity - so do not dump it there.Toothpick
@Toothpick that is strange as MSDN (and actually many others) supply examples for extending the IdentityUser (blogs.msdn.com/b/webdev/archive/2013/10/16/…). They seem to add additional data to the IdentityUser. I understand you don't like the way the model has been build, but can it work? Thank you for your comments BTW.Geographical
It breaks SOLID principles. People making examples normally do not think about maintainability and other irrelevant factors. Especially MSDN is famous for making examples out of antipatterns and worst practices. Adding data is ok - but not adding hugh amounts. Keep the ASP.NET level idntity an object only used for this (entity id, roles etc.) and then load the real object when you need it. Do not tie your application level business objects to Identity. THis is turning best practices upside down.Toothpick
@Toothpick with the way you propose the model would the user objects, besides their own id en additional custome fields ofcourse, contain an id which links to the IdentityUser correct? Otherwise i don't understand how i know, and which type of user, logged in. I need to make a correlation somewhere right?Geographical
If setting the state to added causes an DbEntityValidationException then that you have moved pas the posted problem but you are now seeing a second problem that was not apparent because of the problem you have posted. The exception is caused invalid data, if you inspect the exception you should get appropriate message that tell you what is wrong with the data you are trying to save.Bartonbartosch
Why shouldn't a supplier be allowed to also be a customer?Englert
@ChrFin - A supplier would be allowed to be a customer but with a different account as there are different (asp.net identity) security rules per type of user (e.g. two legged authentication vs. normal login). The bigger problem is that i can't add a virtual application user reference to the user types.Geographical
Thats again bad design IMO. Requiring TFA for suppliers is fine, but THAT can then very well be a customer too, can't it? So simply enable/enforce TFA if the user is a supplier. Other security rules should be role-based anyhow IMO...Englert
E
12

As others do too I think this is a design problem. There are some alternative approaches like:

  1. use roles to define the "user-type" (a user can be supplier AND customer)
  2. make the Supplier and Customer entities a relation not extension of the user

e.g.:

public class ApplicationUser : IdentityUser
{
    public virtual Customer Customer { get; set; }
    public virtual Supplier Supplier { get; set; }
}

public class Customer
{
    [Key]
    public int Id { get; set; }

    public virtual ApplicationUser User { get; set; }
    public string CustomerProperty { get; set; }
}

public class Supplier
{
    [Key]
    public int Id { get; set; }

    public virtual ApplicationUser User { get; set; }
    public string SupplierProperty { get; set; }
}

public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
    public DbSet<Customer> Customers { get; set; }
    public DbSet<Supplier> Suppliers { get; set; }
}

public class ApplicationDbInitializer
             : DropCreateDatabaseAlways<ApplicationDbContext>
{
    protected override void Seed(ApplicationDbContext context)
    {
        var userStore = new UserStore(context);
        var userManager = new UserManager(userStore);
        var roleManager = new RoleManager(roleStore);

        var user = userManager.FindByEmail("[email protected]");
        if (user == null)
        {
            user = new ApplicationUser()
            {
                UserName = "[email protected]",
                Email = "[email protected]"
                Customer = new Customer()
                {
                    CustomerProperty = "Additional Info"
                }
            };

            userManager.Create(user, userPassword);
            roleManager.AddUserToRole("Customer");
        }

        user = userManager.FindByEmail("[email protected]");
        if (user == null)
        {
            user = new ApplicationUser()
            {
                UserName = "[email protected]",
                Email = "[email protected]",
                Supplier = new Supplier()
                {
                    IBAN = "212323424342234",
                    Relationship = "OK"
                }
            };

            userManager.Create(user, userPassword);
            roleManager.AddUserToRole("Supplier");
        }
    }
}

and in your logic you can do something like:

if (User.IsInRole("Customer"))
{
    // do something
}

DISCLAIMER: This is not a "copy&paste" example and should just give you an idea of a different approach.

Englert answered 21/11, 2014 at 12:1 Comment(5)
an excellent example but don't the Supplier and Customer objects need their own key (e.g. SupplierId & CustomerId)? And I don't yet understand how the relation between the SupplierId, CustomerId and the ApplicationUser is known on a database level. Does the ApplicationUser has foreign keys towards the Supplier and Customer or the other way around? How is this enforced int he code besides linking the objects using virtual properties?Geographical
need their own key - yes, as disclaimed not a c&p example, but I added them now. how the relation between the SupplierId, CustomerId and the ApplicationUser is known on a database level - the public virtual ApplicationUser User { get; set; } navigation property will be converted to a FK by EF.Englert
This works well if i have i only have the virtual relationship inthe ApplicationUser side. If i also add this virtual relationshop towards the ApplicationUser in the Supplier object i get the: 'Unable to determine the principal end of an association between the types 'ApplicationUser' and 'Supplier'. The principal end of this association must be explicitly configured using either the relationship fluent API or data annotations.' exception. As i also only want 1 type of user (supplier/customer) associated with the ApplicationUser i thought of using an interface. this doesn't work?Geographical
Can you update the question with your current code? If you defined it correctly this shouldn't be a problem. I have multiple of such relations "on my users"...Englert
appending: '[Key, ForeignKey("ApplicationUser")]' to the user types resolved the issue of the navigating between the user to to the applicatiouser :)Geographical
A
6

I just resolved a similar problem. I created a navigation property of abstract type DomainUser in my AppUser (that inherits from Identity User)

public class AppUser : IdentityUser
{
    public DomainUser DomainUser { get; set; }
}

DomainUser looks like this:

public abstract class DomainUser : IAggregateRoot
{
    public Guid Id { get; set; }
    public AppUser IdentityUser { get; set; }
}

I inherit from DomainUser in all concrete domain user types:

public class AdministrationUser : DomainUser
{
    public string SomeAdministrationProperty { get; set; }
}

public class SupplierUser : DomainUser
{
    public string SomeSupplierProperty { get; set; }
}

public class Customer : DomainUser
{
    public string SomeCustomerProperty { get; set; }
}

And in DbContext in OnModelCreating method I configured Entity Framework to store all entities inherited from DomainUser in separate tables (it's called Table per Concrete Type). And configured one to one relationship between IdentityUser and DomainUser:

modelBuilder.Entity<DomainUser>()
            .Map<AdministrationUser>(m =>
            {
                m.MapInheritedProperties();
                m.ToTable("AdministrationUsers");
            })
            .Map<SupplierUser>(m =>
            {
                m.MapInheritedProperties();
                m.ToTable("SupplierUsers");
            })
            .Map<Customer>(m =>
            {
                m.MapInheritedProperties();
                m.ToTable("Customers");
            });

modelBuilder.Entity<DomainUser>()
            .HasRequired(domainUser => domainUser.IdentityUser)
            .WithRequiredPrincipal(groomUser => groomUser.DomainUser);

This code added column "DomainUser_Id" to table AspNetUsers and now I'm able to access IdentityUser navigation property in each domain user and DomainUser navigation property in AppUser.

Anamariaanamnesis answered 18/11, 2016 at 16:49 Comment(0)
C
0

Dont hate the player on this one...

I've inherited code which is production code so can't make too many changes too quick. Trying to do the upgrade from .netframework to core and I've run into the exact same problem. An application user inheriting from Identityuser with a .ToTable mapping.

However I was able to get away with using the TPH (Table per Heirarchy) design they had started because they had used a Discriminator in the table. So I could modify the datacontext simply enough to get onto the next problem:

public class ApplicationUser : IdentityUser
{
    public const int USERNAME_MAX_LENGTH = 60;

    public string Discriminator { get; set; } = "ApplicationUser";

Old Data context (DbModelBuilder):

var applicationUser = modelBuilder
            .Entity<ApplicationUser>()
            .HasKey(au => au.Id)
            .ToTable("IdentityUser");

New version (ModelBuilder):

   var applicationUser = modelBuilder
            .Entity<ApplicationUser>();

   applicationUser
      .HasDiscriminator<string>("Discriminator");

The IdentityUser table already had the Discriminator column in as part of the initial TPH design so I could just make reference to that.

Credit to this article that gave a simple example of TPH vs TPT: Differences between TPT & TPH in EF Core

Cartagena answered 4/4, 2024 at 11:27 Comment(0)

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