EF 4.1中的XML数据类型代码优先 [英] XML data type in EF 4.1 Code First

问题描述

根据这个线程可以将这样的列映射到字符串类型：

  public class XmlEntity 
 {
 public int Id {get;组; } 
 
 [Column（TypeName =xml）] 
 public string XmlValue {get;组; } 
} 
  

该表通过此定义在datebase中正确生成。新的 XmlEntity 对象也可以创建。

但是我尝试从数据库中获取一些实体：

  var entity = db.XmlEntities.Where（e => e.Id == 1）.FirstOrDefault（）; 
  

发生错误：

在模型生成期间检测到一个或多个验证错误
System.Data.Edm.EdmEntityType ：EntityType' XElement '没有键定义。定义此EntityType的密钥。

解决方案

问题是我的包装属性： p>

  [NotMapped] 
 public XElement XmlValueWrapper 
 {
 get {return XElement.Parse（XmlValue） ; } 
 set {XmlValue = value.ToString（）; } 
} 
  

我没有指定 NotMapped 属性。

I would like to use SQL Server xml type as a column type for an entity class.

According to this thread it's possible to map such a column to string type:

public class XmlEntity
{
   public int Id { get; set; }

   [Column(TypeName="xml")]
   public string XmlValue { get; set; }
}

The table is correctly generated in the datebase by this definition. New XmlEntity objects are also can be created.

But then I try to get some entity from the database:

var entity = db.XmlEntities.Where(e => e.Id == 1).FirstOrDefault();

An error occurs:

One or more validation errors were detected during model generation System.Data.Edm.EdmEntityType: EntityType 'XElement' has no key defined. Define the key for this EntityType.

解决方案

The problem was with my wrapper property:

[NotMapped]
public XElement XmlValueWrapper
{
    get { return XElement.Parse(XmlValue); }
    set { XmlValue = value.ToString(); }
}

I didn't specified NotMapped attribute.

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