如何在ASP.NET MVC中映射許多一對多關系？

Question

我有幾個域模型- Address ， Customer ， Employee ， StoreLocation 。 Address與Customer和Employee具有多對一關系，而與StoreLocation具有一對一的關系。

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; }
}

如何映射這種關系？ 我正在使用ASP.NET MVC 3.0和Entity Framework 4.1。

Answer 1

如果您使用的是代碼優先（我想您需要這樣做，否則，您必須編輯您的Q），第一種方法是下面說明的方法：

實體：

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; }
}

dbContext繼承的類：

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);
    }
}

上下文初始化器：

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

    }
}

這將在下面創建db模式： 讓我知道您是否有任何疑問或需要澄清。