使用自定义列名映射外键 [英] Mapping a foreign key with a custom column name

问题描述

我使用的是使用Entity Framework 4.3的代码。我收到以下错误：

System.InvalidOperationException：类型WidgetDistributor.WidgetEntity上的属性WidgetSequence的ForeignKeyAttribute不是有效。在依赖类型WidgetDistributor.WidgetEntity上找不到外键名称WIDGETSEQUENCE_ID。名称值应为逗号分隔的外键属性名称列表。

我的实体是这样的：

  [表（WIDGETENTITIES）] 
 public class WidgetEntity {
 
 [Column（WIDGETENTITY_ID）] 
 public int Id {get;组; } 
 
 [ForeignKey（WIDGETSEQUENCE_ID）] 
 public WidgetSequence Sequence {get;组; } 
 
 //和其他正确映射的属性
} 
 
 [表（WIDGETSEQUENCES）] 
 public class WidgetSequence {
 
 [Column（WIDGETSEQUENCE_ID）] 
 public int Id {get;组; } 
 
 [Column（NUMBER）] 
 public int Number {get;组; } 
} 
  

我的代码似乎正确。我在这里做了什么错？

解决方案

ForeignKey attibute expects a您的类中的属性名称作为参数，但是您指定了列名。使用流畅的映射。

  protected override void OnModelCreating（DbModelBuilder modelBuilder）
 {
 
 modelBuilder .Entity< WidgetEntity>（）
 .HasRequired（w => w.Sequence）
 .WithMany（）
 .Map（m => m.MapKey（WIDGETSEQUENCE_ID）） ; 
} 
  

I'm using Entity Framework 4.3 code-first with Oracle. I'm getting the following error:

System.InvalidOperationException : The ForeignKeyAttribute on property 'WidgetSequence' on type 'WidgetDistributor.WidgetEntity' is not valid. The foreign key name 'WIDGETSEQUENCE_ID' was not found on the dependent type 'WidgetDistributor.WidgetEntity'. The Name value should be a comma separated list of foreign key property names.

My entities are like this:

[Table("WIDGETENTITIES")]
public class WidgetEntity {

    [Column("WIDGETENTITY_ID")]
    public int Id { get; set; }

    [ForeignKey("WIDGETSEQUENCE_ID")]
    public WidgetSequence Sequence { get; set; }

    // and other properties that map correctly
}

[Table("WIDGETSEQUENCES")]
public class WidgetSequence { 

    [Column("WIDGETSEQUENCE_ID")]
    public int Id { get; set; }

    [Column("NUMBER")]
    public int Number { get; set; }
}

My code seems correct. What have I done wrong, here?

解决方案

ForeignKey attibute expects a property name in your class as the argument but you given the column name. Use fluent mappings.

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{

    modelBuilder.Entity<WidgetEntity>()
     .HasRequired(w => w.Sequence)
     .WithMany()
     .Map(m => m.MapKey("WIDGETSEQUENCE_ID"));
}

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