代码首先CTP4 - 如何进行一对一映射？ [英] Code first CTP4 - How to do one to one mapping?

问题描述

我们有一对一的映射类似于此条目所描述的映射，但是我无法使用代码在CTP4中使用它第一种方法。

We have a one to one mapping similar to that described by this entry, however I have been unable to get this to work in CTP4 with the code first approach.

http://blogs.msdn.com/b/adonet/archive/2008/12/05/table-splitting -mapping-multiple-entity-types-to-same-table.aspx

例如这是我们的情况 - 并且都映射到现有数据库中的各个表，并且员工联系人详细信息是可选的（我已经从类中转移了所有额外的属性），并且数据库在两个表中使用相同的EmployeePK
值。

public class EmployeeContact {

public class EmployeeContact {

  [关键] [必填]

  public virtual int EmployeeOID {
get ; set ; }¥b $ b  公共虚拟员工员工  {
get ; set ; }
}



public 班级员工{

  [Key] [Required]
  public virtual int EmployeeOID { get; set; }
  public virtual Employee Employee { get; set; }
}

public class Employee {

  [Key] [必填] [StoreGenerated（StoreGeneratedPattern.Identity）]

  public virtual int EmployeeOID {
get ; set ; }¥b $ b  public virtual EmployeeContact ContactDetails  {
get ; set ; } b $ b}

  [Key][Required][StoreGenerated(StoreGeneratedPattern.Identity)]
  public virtual int EmployeeOID { get; set; }
  public virtual EmployeeContact ContactDetails { get; set; }
}

我们一直在使用映射类，例如

We have been using mapping classes e.g.

public 类 EmployeeMapping：EntityConfiguration< Employee>  {

public class EmployeeMapping: EntityConfiguration<Employee> {

  public EmployeeMapping（）

  public EmployeeMapping()

  {

    this.HasKey（p => p.EmployeeOID）;

    this.HasKey( p => p.EmployeeOID);

this.MapSingleType（p => new {

this.MapSingleType( p => new {

EmployeePK = p.EmployeeOID ，

EmployeePK = p.EmployeeOID,

...

}）。ToTable（" Emp.Employee"）;

}).ToTable("Emp.Employee");

&NBSP; }

}



我尝试过使用RelatedTo（）数据注释并使用this.HasOptional< EmployeeContact>（p = > p.ContactDetails）.WithOptionalDependent（p => p.Employee）;在这种情况下，联系人详细信息是可选的。

}

I have tried using the RelatedTo() data annotations and using this.HasOptional<EmployeeContact>( p => p.ContactDetails).WithOptionalDependent( p => p.Employee); The contact details optional in this case.

它们似乎都不起作用。它不会生成正确的SQL，因为它尝试从名为emp.ContactDetails_Employee的表中读取

None of it seems to work. It does not generate the correct SQL, as it attempts to read from a table called emp.ContactDetails_Employee

谢谢

Myles。

推荐答案

Hi Myles

Hi Myles

我一直在为类似的问题挣扎，以下结果证明是解决方案：

I've been striggling with a similar problem for which the following turned out to be a solution:

using System;
using System.Data.Entity;
using System.Data.Entity.ModelConfiguration;
using System.Data.Entity.Infrastructure;

namespace ERTest
{
  public class Customer
  {
    public int CustomerID
    {
      get;
      set;
    }

    public string Name
    {
      get;
      set;
    }

    public CustomerDetail Details
    {
      get;
      set;
    }
  }

  public class CustomerDetail
  {
    public int CustomerDetailID
    {
      get;
      set;
    }
  
    public int Age
    {
      get;
      set;
    }

    public Customer Customer
    {
      get;
      set;
    }
  }

  public class CustomerDetailMapping : EntityConfiguration<CustomerDetail>
  {
    public CustomerDetailMapping()
    {
      MapSingleType
      (
        d =>
          new
          {
            d.CustomerDetailID,
            d.Age,
            d.Customer.CustomerID
          }
      )
      .ToTable( "CustomerDetails" );
    }
  }

  public class CustomerMapping : EntityConfiguration<Customer>
  {
    public CustomerMapping()
    {
      HasRequired( c=> c.Details ).WithRequiredDependent( d => d.Customer );
    }
  }

  public class TestContext : DbContext
  {
    static TestContext()
    {
      Database.SetInitializer<TestContext>( null );
    }

    public TestContext( DbModel model )
      : base( model )
    {
    }

    public DbSet<Customer> Customers
    {
      get;
      set;
    }

    public DbSet<CustomerDetail> CustomerDetails
    {
      get;
      set;
    }
  }

  class Program
  {
    static void Main( string[] args )
    {
      ModelBuilder builder = new ModelBuilder();
      builder.Configurations.Add( new CustomerMapping() );
      builder.Configurations.Add( new CustomerDetailMapping() );

      TestContext context = new TestContext( builder.CreateModel() );

      foreach ( var c in context.Customers.Include( "Details" ) )
      {
        Console.Out.WriteLine( "{0} {1} {2}", c.CustomerID, c.Name, c.Details.Age );
      }
    }
  }
}

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