asp.net - 将附加属性添加到 Entity Framework 4编码第一个CTP 5实体

Question

我正在使用ASP.NET MVC 3和Entity Framework code first CTP 5。我想知道是否可以添加未映射到表列的其他属性？

我有一个News类，它的定义如下:

public class News : Entity
{
   public int NewsId { get; set; }
   public string Title { get; set; }
   public string Body { get; set; }
   public bool Active { get; set; }
}

我的数据库上下文类:

public class MyContext : DbContext
{
   public DbSet<News> Newses { get; set; }
}

在实体类中，我有一个定义如下的属性:

public IList<RuleViolation> RuleViolations { get; set; }

我还没有编写这部分代码，但是我希望在验证对象时将所有坏规则添加到此列表中。我得到的错误是:

One or more validation errors were detected during model generation:

    System.Data.Edm.EdmEntityType: : EntityType 'RuleViolation' has no key defined. Define the key for this EntityType.
    System.Data.Edm.EdmEntitySet: EntityType: The EntitySet RuleViolations is based on type RuleViolation that has no keys defined.

这是我的存储库代码:

public News FindById(int newsId)
{
   return context.Database.SqlQuery<News>("News_FindById @NewsId",
      new SqlParameter("NewsId", newsId)).FirstOrDefault();
}

更新2011-03-02:

这是我的 Entity类:

public class Entity
{
   public IList<RuleViolation> RuleViolations { get; set; }

   public bool Validate()
   {
      // Still needs to be coded
      bool isValid = true;

      return isValid;
   }
}

这是我的 RuleViolation类:

public class RuleViolation
{
   public RuleViolation(string parameterName, string errorMessage)
   {
      ParameterName = parameterName;
      ErrorMessage = errorMessage;
   }

   public string ParameterName { get; set; }
   public string ErrorMessage { get; set; }
}

这是我的上下文类:

public class MyContext : DbContext
{
   public DbSet<News> Newses { get; set; }

   protected override void OnModelCreating(ModelBuilder modelBuilder)
   {
      modelBuilder.Entity<News>().Ignore(n => n.RuleViolations);
   }
}

Answer 1

您可以使用Fluent API忽略类型，方法是在OnModelCreating类的MyContext方法中添加忽略规则

public class MyContext : DbContext {

  public DbSet<News> Newses { get; set; }

  protected override void OnModelCreating(ModelBuilder builder) {

    builder.Ignore<RuleViolation>()

  }

}

或者，您可以使用 NotMapped属性忽略该属性

public class Enitity {

  [NotMapped]
  public IList<RuleViolation> RuleViolations { get; set; }

  //other properties here

}

然后 Entity Framework 将忽略该属性。