In ASP.NET MVC, how do you map many one-to-many relationships?

c# ef-code-first entity-framework one-to-many

Question

I don't have many domain models.Address , Customer , Employee , StoreLocation . Address has several connections withCustomer and Employee and direct connection to StoreLocation.

public class Address
{
    public int Id;
    public string Line1 { get; set; }
    public string Line2 { get; set; }
    public string Line3 { get; set; }
}

public class Customer
{
    public int Id { get; set; }
    public string Name { get; set; }
    public IList<Address> Addresses { get; set; }
}

public class StoreLocation
{
    public int Id { get; set; }
    public string ShortCode { get; set; }
    public string Description { get; set; }
    public Address Address { get; set; }
}


public class Employee
{
    public int Id { get; set; }
    public string Name { get; set; }
    public DateTime Dob { get; set; }
    public IList<Address> Addresses { get; set; }
}

How can this connection be mapped? I'm using Entity Framework 4.1 and ASP.NET MVC 3.0.

1
0
10/11/2011 9:25:24 AM

Accepted Answer

The first method is the one described below if you are using code-first (I assume you want this; if not, you must alter your Q):

Entities:

public class Address {
    [Key]
    public int Id { get; set; }
    public string Line1 { get; set; }
    public string Line2 { get; set; }
    public string Line3 { get; set; }

    public virtual Customer Customer { get; set; }
    public virtual StoreLocation StoreLocation { get; set; }
    public virtual Employee Employee { get; set; }

    public int? CustomerId { get; set; }

    public int? EmployeeId { get; set; }
}

public class Customer {
    [Key]
    public int Id { get; set; }
    public string Name { get; set; }
    public virtual ICollection<Address> Addresses { get; set; }
}

public class StoreLocation {
    [Key]
    public int Id { get; set; }
    public string ShortCode { get; set; }
    public string Description { get; set; }
    public virtual Address Address { get; set; }
}


public class Employee {
    [Key]
    public int Id { get; set; }
    public string Name { get; set; }
    public DateTime Dob { get; set; }
    public virtual ICollection<Address> Addresses { get; set; }
}

inheriting class: 15-zzz

public class ManyOneToManyContext : DbContext {

    static ManyOneToManyContext() {
        Database.SetInitializer<ManyOneToManyContext>(new ManyOneToManyInitializer());
    }

    public DbSet<Address> Addresses { get; set; }
    public DbSet<Customer> Customers { get; set; }
    public DbSet<StoreLocation> StoreLocations { get; set; }
    public DbSet<Employee> Employees { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder) {

        modelBuilder.Conventions.Remove<IncludeMetadataConvention>();

        modelBuilder.Entity<Customer>().HasMany(c => c.Addresses).WithOptional(a => a.Customer).HasForeignKey(a => a.CustomerId);

        modelBuilder.Entity<StoreLocation>().HasRequired(s => s.Address).WithOptional(a => a.StoreLocation).Map(t => t.MapKey("AddressId"));

        modelBuilder.Entity<Employee>().HasMany(e => e.Addresses).WithOptional(a => a.Employee).HasForeignKey(e => e.EmployeeId);
    }
}

Initializer for Context:

public class ManyOneToManyInitializer : DropCreateDatabaseAlways<ManyOneToManyContext> {
    protected override void Seed(ManyOneToManyContext context) {

    }
}

This will produce the following db-schema:Many one-to-many relationship Please let me know if there are any parts that are unclear or if you have any queries.

13
10/10/2011 11:22:17 PM


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