多个对象集的相同类型的 [英] Multiple object sets of the same type

问题描述

我试图创造EF5 RC类似这样的数据上下文：

 类WordContext：的DbContext {
公共DbSet< Word和GT; PossibleWords {搞定;组; } 
公共DbSet< Word和GT; UsedWords {搞定;组; } 
} 
  

当我试图更新数据库，我收到一个异常说：每种类型的多个对象集，不支持。该对象集PossibleWords'和'UsedWords可以同时包含类型'TestProject.Word的实例。的

一些google搜索后，看来一个结构像这样的数据上下文实际上不可能在EF

我的问题是：什么是好的代码，第一个设计来存储这样的数据

我猜是小事一桩可能是这样的：

 类WordContext：{的DbContext 
公共DbSet<单词GT;个字{搞定;组; } 
} 
 
类词{
公众诠释ID {搞定;组; } 
公众的IList<串GT; PossibleWords {搞定;组; } 
公众的IList<串GT; UsedWords {搞定;组; } 
} 
  

但是，这只是感觉可怕

编辑：当然，另一种很普通的是使用2种不同的Word类型，如

类PossibleWord {。 ..}
类BannedWord {...}

其实，现在我把它写下来，它甚至不看坏，嗯...

EDIT2：

以防万一别人运行到这个也是，我将展示它是如何解决中底：

 类字{
 [关键] 
公共字符串字符串{搞定;组; } 
} 
类PossibleWord：字{} 
类UsedWord：字{} 
 
类WordContext：的DbContext {
公共DbSet< PossibleWord> PossibleWords {搞定;组; } 
公共DbSet< UsedWord> UsedWords {搞定;组; } 
} 
  

解决方案

想必你想代表你的原码2个不同的表。我会考虑两个类，UsedWord和PossibleWord，只是有两个人实现共同的接口，说：IWord？或者更简单的，只是有一个布尔IsUsed领域的话语，一个表/类型。

I tried to create a data context in EF5 RC similar to this:

class WordContext : DbContext {
    public DbSet<Word> PossibleWords { get; set; }
    public DbSet<Word> UsedWords { get; set; }
}

When I tried to update the database, I received an exception saying: Multiple object sets per type are not supported. The object sets 'PossibleWords' and 'UsedWords' can both contain instances of type 'TestProject.Word'.

After some googling, it appears that structuring a data context like this is not actually possible in EF.

My question is: What's a good code-first design to store data like this?

I guess a trivial one could be something like:

class WordContext : DbContext {
    public DbSet<Words> Words { get; set; } 
}

class Words {
    public int ID { get; set; }
    public IList<string> PossibleWords { get; set; }
    public IList<string> UsedWords { get; set; }
}

But this just feels terrible.

Edit: Of course, another trivial one would be to use 2 different Word types, like

class PossibleWord { ... } class BannedWord { ... }

Actually, now that I wrote it down it doesn't even look that bad, hmm...

Edit2:

Just in case someone else runs into this too, I'll show how it was solved in the end:

class Word {
    [Key]
    public string String { get; set; }
}
class PossibleWord : Word { }
class UsedWord : Word { }

class WordContext : DbContext {
    public DbSet<PossibleWord> PossibleWords { get; set; }
    public DbSet<UsedWord> UsedWords { get; set; }
}

解决方案

Presumably you are trying to represent 2 different tables in your original code. I would consider two classes, UsedWord and PossibleWord, and just have both of them implement a common interface, say: IWord? Or simpler, just have a bool "IsUsed" field on Word, and one table/type.

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