映射字典< string，string> [英] Mapping a Dictionary<string, string>

问题描述

大家好！

我有以下数据库结构：

CREATE TABLE [Category]
(
	[Id] [bigint] IDENTITY(1,1) NOT NULL,
	[WordId] [bigint] NOT NULL,
	[ParentCategoryId] [bigint] NULL,
	PRIMARY KEY ([Id]),
	FOREIGN KEY([ParentCategoryId]) REFERENCES [Category] ([Id]),
	FOREIGN KEY([WordId]) REFERENCES [Word] ([Id])
);

CREATE TABLE [WordTranslation]
(
	[Id] [bigint] IDENTITY(1,1) NOT NULL,
	[WordId] [bigint] NOT NULL,
	[LanguageCode] [nvarchar](10) NOT NULL,
	[Value] [nvarchar](1000) NOT NULL,
	PRIMARY KEY ([Id]),
	FOREIGN KEY([WordId]) REFERENCES [Word] ([Id])
);

CREATE TABLE [Word]
(
	[Id] [bigint] IDENTITY(1,1) NOT NULL,
	[Guid] [uniqueidentifier] NOT NULL,
	PRIMARY KEY ([Id])
);

我想针对以下类映射：

namespace A
{
  public interface IEntity
  {
    long Id { get; set; }
  }

  public class Category : IEntity
  {
    public virtual long Id { get; set; }

    public virtual long WordId { get; set; }

    public virtual Word Word { get; set; }

    public virtual long? ParentCategoryId { get; set; }

    public virtual Category ParentCategory { get; set; }

    public virtual ICollection<Category> SubCategories { get; set; }
  }

  public class Word : IEntity
  {
    public virtual long Id { get; set; }

    public virtual Guid Guid { get; set; }

    public virtual IDictionary<string, string> Translations { get; set; }
  }

  public class WordTranslation : IEntity
  {
    public virtual long Id { get; set; }

    public virtual string Value { get; set; }

    public virtual string LanguageCode { get; set; }
  }
}

 

我可以映射类别 - >好一点，没问题。问题是将Word.Translations映射到WordTranslation。

I can map the Category -> Word fine, that's no problem. The problem is mapping the Word.Translations against the WordTranslation.

Translations键应为WordTranslation.LanguageCode，Translations值应为WordTranslations.LanguageCode。

The Translations key should be WordTranslation.LanguageCode and the Translations value should be WordTranslations.LanguageCode.

甚至可以用仅代码/代码优先映射它吗？

Is it even possible to map this with code-only/code-first?

 

我想工作的场景：

// Retrieval
var category = context.Categories.First(x => x.Id == 50);

var englishName = category.Word.Translations["en-US"];
var swedishName = category.Word.Translations["sv-SE"];

// Insertion
category.Word.Translations["en-GB"] = "...";

// This should result in an INSERT INTO [WordTranslation] ([WordId], [LanguageCode], [Value]) VALUES (Word.Id, "en-GB", "...");
context.SaveChanges();

// Kim Johansson

// Kim Johansson

推荐答案

我认为EF不会将其视为字典而是将其视为ICollection< T>。

I don't think EF would treat it as a dictionary but just as an ICollection<T>.

var englishName = category.Word.Transaltions.Single（t => ; t.LanguageCode ==" en-US"）;

var englishName = category.Word.Transaltions.Single(t => t.LanguageCode == "en-US");

这篇关于映射字典&lt; string，string&gt;的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！