CODEWITHSUNDEEP
c#asp.net-mvc-3entity-framework
Slinky
Slinky

Reputation: 5832

Creating CodeFirst Model with Foreign Keys

I am new to ASP.NET and EF but have Ruby MVC experience. I am working on a complex app that has one to many relationships so I created a smaller project that I can play with and test out CodeFirst generation and what could be more fun than testing with a guitar project! All of you musicians out there know about the one to many relationship as in one guitarist owns several guitars and amplifiers. This code works in that it creates the database and tables when I seed it - Just would like some advice on how to do it better and any possible gotchas?

Thanks

namespace GuitarCollector.Models
{
 public class Guitarist
 {

    public Guitarist()
    {
        Guitars = new List<Guitar>();
        Amplifiers = new List<Amplifier>();
    }

    public int Id { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }
    public List<Guitar> Guitars { get; set; }
    public List<Amplifier> Amplifiers { get; set; }
}

public class Guitar
{
    //Primary Key
    public int Id { get; set; }
    //Foreign Key
    public int GuitaristId { get; set; }

    public int YearOfManufacture { get; set; }
    public string Make { get; set; }
    public string Model { get; set; }
    public string Finish { get; set; }
    public string SerialNumber { get; set; }
    public double AppraisedValue { get; set; }

    Guitarist Guitarist { get; set; }
}

 public class Amplifier
{
    //Primary Key
    public int Id { get; set; }
    //Foriegn Key
    public int GuitaristId { get; set; }

    public int YearOfManufacture { get; set; }
    public int Wattage { get; set; }
    public string Make { get; set; }
    public string Model { get; set; }
    public string SerialNumber { get; set; }
    public double AppraisedValue { get; set; }

    public Guitarist Guitarist { get; set; }
}

}

namespace GuitarCollector.DAL { public class GuitaristContext : DbContext {

    public DbSet<Guitarist> Guitarists { get; set; }
    public DbSet<Guitar> Guitars { get; set; }
    public DbSet<Amplifier> Amplifiers { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);
        modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
    }
}

}

Upvotes: 1

Views: 112

Answers (2)

Tarzan
Tarzan

Reputation: 4538

You might want to use "public virtual ICollection" rather than "public List". However, what you wrote looks good.

public virtual ICollection<Guitar> Guitars{ get; set; }

The reason to use "public virtual ICollection" is to get Deferred Loading support. Coming form a fellow guitarist, rock on!

Upvotes: 1

trinaldi
trinaldi

Reputation: 2950

The way you set up your POCOs seems to be OK. Code First will do the FK trick by itself. Set your List<T> as virtual so EF can use Lazy Loading!

If you really want to setup, use the Fluent API at your DAL:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    base.OnModelCreating(modelBuilder);
    modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
    modelBuilder.Entity<Guitarist>().HasRequired(p => p.Guitar).WithMany(b => b.Amplifier)
}

Great idea, by the way!

Upvotes: 1

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