Many to Many relationship in Asp.Net MVC 5 with Identity table and Custom table

Question

I'm trying to make a relationship between the Users from the table generated by Asp.Net Identity with my own table. The relationship must be many to many, since many Users can work on the same Task (which is my table), and same time an User can work on multiple Tasks.

public class Task
{      
    public int ID { get; set; }
    public string Name { get; set; }

    public string UserID { get; set; }

    public virtual ICollection<ApplicationUser> Users { get; set; }
}

public class ApplicationUser : IdentityUser
{
    public int TaskID { get; set; }
    public virtual ICollection<Task> Tasks{ get; set; }

    // rest of the code
}

I try it this way but I get an error during migration (or run time)

"One or more validation errors were detected during model generation:"

Please help me solve this problem and archive what I need.

Ermir Beqiraj · Accepted Answer · 2016-09-24T17:22:54.767

4

Try it like this:

public class Projects
{
    public Projects()
    {
        ApplicationUser = new HashSet<ApplicationUser>();
    }
    public int Id { get; set; }
    public string Name { get; set; }
    public virtual ICollection<ApplicationUser> ApplicationUser { get; set;     }
}

Application User



    public class ApplicationUser : IdentityUser
    {
        public ApplicationUser()
        {
            Projects = new HashSet<Projects>();
        }
        public async Task GenerateUserIdentityAsync(UserManager manager)
        {
            // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
            var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
            // Add custom user claims here
            return userIdentity;
        }        
        public virtual ICollection <Projects > Projects { get; set; }
    }

Application Context :



    public class ApplicationDbContext : IdentityDbContext
    {
        public ApplicationDbContext()
            : base("DefaultConnection", throwIfV1Schema: false)
        {
        }
        public virtual DbSet<Projects> Projects { get; set; }

        public static ApplicationDbContext Create()
        {
            return new ApplicationDbContext();
        }
    }

now when I run this Mvc app and register, the db tables I get is like the following:

and the correct schema:

The things to be questioned are a lot, from my point of view important is to determine if you: - can/should you mix application context and your model context ?

edited Sep 24 '16 at 17:22

answered Sep 24 '16 at 14:11

Ermir Beqiraj

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I would prefer to keep my finger away from ApplicationDbContext – Arianit Sep 24 '16 at 14:42
1

There is no way that you could use two different contexts with two dufferent tables and then query them in thr same linq query. You are restricted to use one context. – Ermir Beqiraj Sep 24 '16 at 14:59
can you show those little changes ? hope it'll help others @Arianit – Sampath Sep 24 '16 at 15:48
What changes @Arianit? It worked like that in my side. – Ermir Beqiraj Sep 24 '16 at 16:05
is this correct `public virtual ICollection ApplicationUser { get; set; }` ? @E.B – Sampath Sep 24 '16 at 16:15
The problem is with the HashSets.It gives an error the way how you did it. – Arianit Sep 24 '16 at 16:17
Ah, editor has removed the signs "<" & ">" for collection – Ermir Beqiraj Sep 24 '16 at 17:06
1

They are supposed to be in the way that a collection is written, like : public virtual ICollection ApplicationUser{get;set} , but in markdown the sign "<" has removed the rest of row... I'll edit it. – Ermir Beqiraj Sep 24 '16 at 17:14
ok, it must be ok now. seriously replaced all of them with < and > , I'll find a smarter way for another time :D ... – Ermir Beqiraj Sep 24 '16 at 17:24
I'm waiting for that smarter way – Arianit Sep 24 '16 at 19:05

score 1 · Answer 2 · edited May 23 '17 at 10:27

1

You can try it as shown below using Fluent API.

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{

    modelBuilder.Entity<Task>()
                .HasMany<ApplicationUser>(s => s.Users)
                .WithMany(c => c.Tasks)
                .Map(cs =>
                        {
                            cs.MapLeftKey("TaskRefId");
                            cs.MapRightKey("ApplicationUserRefId");
                            cs.ToTable("TaskApplicationUser");
                        });

}

Update : you can see this link too.

EntityType 'IdentityUserLogin' has no key defined. Define the key for this EntityType

edited May 23 '17 at 10:27

Community

1
1

answered Sep 24 '16 at 12:33

Sampath

63,341
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this must be in my own context class not in the ApplicationDbContext class, right? – Arianit Sep 24 '16 at 12:35
I didn't get you ? – Sampath Sep 24 '16 at 12:37
there are 2 context classes, the one for the Identity that Asp.Net generates for me, called ApplicationDbContext. And the other context I made myself. So this code you wrote as answer must be in my Context class I guess. OR? – Arianit Sep 24 '16 at 12:39
Yes,use your `context`. – Sampath Sep 24 '16 at 12:41
did you try with the other `context` too ? – Sampath Sep 24 '16 at 12:45
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/124101/discussion-between-arianit-and-sampath). – Arianit Sep 24 '16 at 12:46
1

please see the **Update**. – Sampath Sep 24 '16 at 13:49

Ryan · Answer 3 · 2016-09-24T14:56:22.670

1

Error text is not related to your many-to-many relationship. It tips that other built-in entities are not configured properly. So, It would be nice if you provided full definition of your custom DbContext-class and how it is configured.

UPDATE

As i understood u are working with two different contexts. You must work with the same context, cause of u are extending IdentityContext, creating relationships and adding custom types. So problem then will be resolved itself. Hope, this will help.

edited Sep 24 '16 at 14:56

answered Sep 24 '16 at 14:29

Ryan

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but is it an acceptable practice to use the applicationdbcontext to work with the business logic? – Arianit Sep 24 '16 at 16:13
1

Don't forget - it is just **DbContext**. ApplicationDbContext serves as repository itself. Every business logic needs a repository to persist or read data. Simple solutions can use ApplicationDbContext directly, in complex - u create ur own repositories. Also this is a bunch with authentication system. – Ryan Sep 24 '16 at 18:03
but what bothers me is that in the future when I need to work with my custom db table, example reference it from an other table or to another table, I have to work with the ApplicationDbContext! This is a thing I kinda don't like. I want to use the ApplicationDbContext just for Identity – Arianit Sep 24 '16 at 23:09

Many to Many relationship in Asp.Net MVC 5 with Identity table and Custom table

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