CODEWITHSUNDEEP
c#entity-framework
Joseph
Joseph

Reputation: 93

Entity Framework Adding Duplicate Values

I am new to EF and I am trying to work with a many-to-many relationship.

I have a Developers table and I have a Applications table.

Each developer can have many applications, and each application can have many developers.

I have tried to follow examples on StackOverflow where it mentions to attach, but I've tried everything and it still creates duplicate developers for an application.

public class Developer 
    {
        public int DeveloperId { get; set; }
        [Required]
        public string DeveloperName { get; set; }
        public virtual List<Application> Applications { get; set; }
    }

public class Application 
    {
        public int Id { get; set; }
        [Required]
        public string Name { get; set; }
        [Required]
        public string Description { get; set; }
        public string Note { get; set; }
        public Developer Owner { get; set;}
        public virtual List<Developer> Developers { get; set; }
    }

protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {

            modelBuilder.Entity<Developer>()
                .HasMany<Application>(d => d.Applications)
                .WithMany(a => a.Developers)
                .Map(ad =>
                {
                    ad.MapLeftKey("DeveloperRefId");
                    ad.MapRightKey("ApplicationRefId");
                    ad.ToTable("DeveloperApplication");
                });
        }

Above describes my setup. I've tried so many things, but any time a new application is added, EF creates a new developer to associate with it.

                context.Applications.Add(app);
                   // no matter what I try here I get a duplicate developer
                context.SaveChanges();
                return Ok(app.Id);

Any suggestions would be greatly appreciated! Thank you!

Upvotes: 0

Views: 36

Answers (1)

henoc salinas
henoc salinas

Reputation: 1054

Change:

public class Application 
{
    public int Id { get; set; }
    [Required]
    public string Name { get; set; }
    [Required]
    public string Description { get; set; }
    public string Note { get; set; }
    public Developer Owner { get; set;}
}

To:

public class Application 
{
    private List<Developer> _Developers; 
    public int Id { get; set; }
    [Required]
    public string Name { get; set; }
    [Required]
    public string Description { get; set; }
    public string Note { get; set; }

    [Required(ErrorMessage="The Id Of Owner(owner as a developer) is Required")]
    public int DeveloperId { get; set; } 

    [ForeignKey("DeveloperId")]
    public virtual Developer Owner { get; set;}


    public virtual List<Developer> Developers { get{return _Developers;}} // This create Many to many

    public application(){
        _Developers= new List<Developer>();
    }
}

Upvotes: 1

Related Questions