配置许多实体框架代码优先和流利的API一比一的关系 [英] Configuring many One-To-One relationships with Entity Framework Code First and Fluent API

问题描述

我有一个可怕的数据库模型（在MySQL中，虽然我不认为事情），别人设计的，所以我坚持了下来，但仍要与实体框架使用它：

I have a horrible database model (in MySQL though I don't think that matters) that someone else designed so I'm stuck with it, but want to use with Entity Framework with it anyway:

项目

ASSET_ID*   ASSET_NAME  FIELDS_ID
1          Cat         1
2          Dog         2
3          Fish        3

ItemFields

ID*    CUSTOMFIELD1ID    CUSTOMFIELD2ID    CUSTOMFIELD3ID
1     1001              1002              1003
2     1004              1005              1006
3     1007              1008              1009

字段

ID*    STRINGVAL
1001   Meow Mix
1002   House
1003   5lbs
1004   Kibble
1005   Yard
1006   30lbs
1007   Fish Food
1008   Tank
1009   0.5 ounces

*指示表的PK

---

*indicates table's PK

---

最后，我想配置的关系，这样我就可以得到这样的自定义数据：

Ultimately, I'm trying to configure the relationships so I can get custom data like this:

Item item = GetItem(1);
item.Food.ToString(); // Output: meow mix
item.Place.ToString(); // Output: house
item.Weight.ToString(); // Output: 5 lbs 

...等。但老实说，我想在这一点上解决这个：

...etc. but honestly I'd settle for this at this point:

Item item = GetItem(1);
Item.ItemFields.CustomField3.Value // Output: 5 lbs
Item item = GetItem(2);
Item.ItemFields.CustomField2.Value // Output: Yard
Item item = GetItem(3);
Item.ItemFields.CustomField1.Value // Output: Fish Food

---

---

到目前为止，我已经得到了这一点：

So far I've got this:

一比一：项目 - ItemFields

modelBuilder.Entity<Item>()
    .HasRequired(x => x.ItemFields)
    .WithRequiredPrincipal(y => y.Item);

但ItemFields.CustomField1ID到Field.ID有关映射是什么？

But what about mapping ItemFields.CustomField1ID to Field.ID?

它甚至有可能来配置这样的使用EF代码首先有关系吗？我很困惑这是否是一个一对一或一对多......我认为它实际上是是众多一到那些（如果是有道理的）。

Is it even possible to configure a relationship like this using EF code first? I'm pretty confused about whether or not this is a one-to-one or a one-to-many... I think what it actually is is many one-to-ones (if that makes sense).

有什么建议？

推荐答案

我可能已经想通了这一点。我编辑我的ItemFields类是这样的：

I may have figured this out. I edited my ItemFields class to look like this:

public class ItemFields
{
    public int Id { get; set; }
    public int CUSTOMFIELD1ID { get; set; }
    public virtual Field CustomField1 { get; set; }

和则配置了这些关系：

modelBuilder.Entity<Item>()
    .HasRequired(x => x.CustomField1)
    .WithMany()
    .HasForeignKey(x => x.CUSTOMFIELD01_ID);
modelBuilder.Entity<Item>()
    .HasRequired(x => x.CustomField2)
    .WithMany()
    .HasForeignKey(x => x.CUSTOMFIELD02_ID);

和它似乎已经奏效，但说实话，我不完全理解为什么。我还是最想要将它们映射到更加人性化的类。

And it seems to have worked, though to be honest I don't fully understand why. I'd still ideally like to map them to more user-friendly classes.

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