我正在使用EF Code First开发域模型以持久化数据。我需要添加多语言支持,但不想在域模型中加入位置概念。
我希望数据库中存在一个ProductTranslate表,包含标题和语言字段,但在我的域中,标题属于Product实体。
有人知道如何实现吗?
我希望数据库中存在一个ProductTranslate表,包含标题和语言字段,但在我的域中,标题属于Product实体。
有人知道如何实现吗?
这是我使用的,与 Code First 很好地配合。
定义一个基础的 Translation
类:
using System;
public abstract class Translation<T> where T : Translation<T>, new()
{
public Guid Id { get; set; }
public string CultureName { get; set; }
protected Translation()
{
Id = Guid.NewGuid();
}
}
TranslationCollection
类:using System.Collections.ObjectModel;
using System.Globalization;
using System.Linq;
public class TranslationCollection<T> : Collection<T> where T : Translation<T>, new()
{
public T this[CultureInfo culture]
{
get
{
var translation = this.FirstOrDefault(x => x.CultureName == culture.Name);
if (translation == null)
{
translation = new T();
translation.CultureName = culture.Name;
Add(translation);
}
return translation;
}
set
{
var translation = this.FirstOrDefault(x => x.CultureName == culture.Name);
if (translation != null)
{
Remove(translation);
}
value.CultureName = culture.Name;
Add(value);
}
}
public T this[string culture]
{
get
{
var translation = this.FirstOrDefault(x => x.CultureName == culture);
if (translation == null)
{
translation = new T();
translation.CultureName = culture;
Add(translation);
}
return translation;
}
set
{
var translation = this.FirstOrDefault(x => x.CultureName == culture);
if (translation != null)
{
Remove(translation);
}
value.CultureName = culture;
Add(value);
}
}
public bool HasCulture(string culture)
{
return this.Any(x => x.CultureName == culture);
}
public bool HasCulture(CultureInfo culture)
{
return this.Any(x => x.CultureName == culture.Name);
}
}
然后您可以在实体中使用这些类,例如:
using System;
using System.Globalization;
public class HelpTopic
{
public Guid Id { get; set; }
public string Name { get; set; }
public TranslationCollection<HelpTopicTranslation> Translations { get; set; }
public string Content
{
get { return Translations[CultureInfo.CurrentCulture].Content; }
set { Translations[CultureInfo.CurrentCulture].Content = value; }
}
public HelpTopic()
{
Id = Guid.NewGuid();
Translations = new TranslationCollection<HelpTopicTranslation>();
}
}
将 HelpTopicTranslation
定义为:
using System;
public class HelpTopicTranslation : Translation<HelpTopicTranslation>
{
public Guid Id { get; set; }
public Guid HelpTopicId { get; set; }
public string Content { get; set; }
public HelpTopicTranslation()
{
Id = Guid.NewGuid();
}
}
现在,针对代码优先的方面,使用以下配置:
using System.Data.Entity.ModelConfiguration;
using Model;
internal class HelpTopicConfiguration : EntityTypeConfiguration<HelpTopic>
{
public HelpTopicConfiguration()
{
Ignore(x => x.Content); // Ignore HelpTopic.Content since it's a 'computed' field.
HasMany(x => x.Translations).WithRequired().HasForeignKey(x => x.HelpTopicId);
}
}
public class TestContext : DbContext
{
public DbSet<HelpTopic> HelpTopics { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations.Add(new HelpTopicConfiguration());
}
}
当所有这些都完成后,将生成以下迁移:
using System.Data.Entity.Migrations;
public partial class AddHelpTopicTable : DbMigration
{
public override void Up()
{
CreateTable(
"dbo.HelpTopics",
c => new
{
Id = c.Guid(false),
Name = c.String(),
})
.PrimaryKey(t => t.Id);
CreateTable(
"dbo.HelpTopicTranslations",
c => new
{
Id = c.Guid(false),
HelpTopicId = c.Guid(false),
Content = c.String(),
CultureName = c.String(),
})
.PrimaryKey(t => t.Id)
.ForeignKey("dbo.HelpTopics", t => t.HelpTopicId, true)
.Index(t => t.HelpTopicId);
}
public override void Down()
{
DropForeignKey("dbo.HelpTopicTranslations", "HelpTopicId", "dbo.HelpTopics");
DropIndex("dbo.HelpTopicTranslations", new[] { "HelpTopicId" });
DropTable("dbo.HelpTopicTranslations");
DropTable("dbo.HelpTopics");
}
}
欢迎提出任何评论和/或改进意见...