实体框架：将表拆分成多个表 [英] Entity Framework: Split table into multiple tables

问题描述

我有以下表格[PaymentComponent]，使用以下EF代码第一个方法（TPH继承）创建。工作正常我需要更改数据库设计 - 需要在GiftCouponPayment表中存储GiftCouponPayments，并在ClubCard付款表中存储ClubCardPayments。需要在C＃代码中完成哪些更改以获取所需的数据库结构？

I have the following table [PaymentComponent] created using following EF code first approach (TPH inheritance). It works fine. I need to change the database design – need to store GiftCouponPayments in GiftCouponPayment table and ClubCardPayments in ClubCardPayment table. What change need to be done in C# code to get the required database structure?

代码

public abstract class PaymentComponent
{
    public int PaymentComponentID { get; set; }
    public int MyValue { get; set; }
    public string MyType { get; set; }
    public abstract int GetEffectiveValue();
}


public partial class GiftCouponPayment : PaymentComponent
{

    public override int GetEffectiveValue()
    {
        if (MyValue < 2000)
        {
            return 0;
        }
        return MyValue;
    }

}


public partial class ClubCardPayment : PaymentComponent
{
    public override int GetEffectiveValue()
    {
        return MyValue;
    }
}

public partial class Payment
{
    public int PaymentID { get; set; }
    public List<PaymentComponent> PaymentComponents { get; set; }
    public DateTime PayedTime { get; set; }

}



//System.Data.Entity.DbContext is from EntityFramework.dll
public class NerdDinners : System.Data.Entity.DbContext
{

    public NerdDinners(string connString): base(connString)
    { 

    }

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


    public DbSet<GiftCouponPayment> GiftCouponPayments { get; set; }
    public DbSet<ClubCardPayment> ClubCardPayments { get; set; }
    public DbSet<Payment> Payments { get; set; }

}

客户端

static void Main(string[] args)
{
    string connectionstring = "Data Source=.;Initial Catalog=NerdDinners;Integrated Security=True;Connect Timeout=30";

    using (var db = new NerdDinners(connectionstring))
    {
        GiftCouponPayment giftCouponPayment = new GiftCouponPayment();
        giftCouponPayment.MyValue=250;
        giftCouponPayment.MyType = "GiftCouponPayment";

        ClubCardPayment clubCardPayment = new ClubCardPayment();
        clubCardPayment.MyValue = 5000;
        clubCardPayment.MyType = "ClubCardPayment";

        List<PaymentComponent> comps = new List<PaymentComponent>();
        comps.Add(giftCouponPayment);
        comps.Add(clubCardPayment);

        var payment = new Payment { PaymentComponents = comps, PayedTime=DateTime.Now };
        db.Payments.Add(payment);

        int recordsAffected = db.SaveChanges();
    }

}

参考：

1. 如何获取Entity Framework 4.3代码首先使用Table Per Type（TPT）映射子类？


2. http://weblogs.asp.net/manavi/archive/2011/04/24/associations-in-ef-4-1- code-first-part-4-table-splitting.aspx


3. http://www.robbagby.com/entity-framework/entity-framework-modeling-entity-splitting/


4. 实体框架映射方案 - http：//msdn.mi crosoft.com/en-us/library/cc716779.aspx


5. http://blogs.microsoft.co.il/blogs/gilf/archive/2009/03/06/ entity-splitting-in-entity-framework.aspx

1. How do I get Entity Framework 4.3 Code First to map a subclass using Table Per Type (TPT)?
2. http://weblogs.asp.net/manavi/archive/2011/04/24/associations-in-ef-4-1-code-first-part-4-table-splitting.aspx
3. http://www.robbagby.com/entity-framework/entity-framework-modeling-entity-splitting/
4. Entity Framework Mapping Scenarios - http://msdn.microsoft.com/en-us/library/cc716779.aspx
5. http://blogs.microsoft.co.il/blogs/gilf/archive/2009/03/06/entity-splitting-in-entity-framework.aspx

推荐答案

在你的OnModelCreating中的上下文类：

In your Context class in OnModelCreating:

modelBuilder.Entity<GiftCouponPayment>()
                .Map(m =>
                {
                    m.MapInheritedProperties();
                    m.ToTable("GiftCouponPayment");
                });

modelBuilder.Entity<ClubCardPayment>()
                .Map(m =>
                {
                    m.MapInheritedProperties();
                    m.ToTable("ClubCardPayment");
                });

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