Question

说我有2张桌子：

Customer
    Id int
    Name varchar
    TypeId int

CustomerType
    Id int
    Type varchar

TypeId是CustomerType的Id的外键。现在我如何加载客户作为EF的实体：

public class Customer
{
    public int Id { get; set; }
    public string Name { get; set; }

    public int TypeId { get; set; }
    [ForeignKey("TypeId")]
    public string Type { get; set; }
}

Type将是CustomerType的Type属性。我在EF5中使用代码优先。它目前无效，我一直收到The navigation property X is not a declared property on type..例外。

Answer 1

您无法将属性映射到单独的表。只有实体可以映射到表。作为解决方法，您可以创建属性，其类型为CustomerType，将映射到第二个表，并将Type属性标记为未映射：

public class Customer
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int TypeId { get; set; }
    [ForeignKey("TypeId")]
    protected CustomerType CustomerType { get; set; }
    [NotMapped]
    public string Type 
    { 
        get { return CustomerType.Type; }
        set { CustomerType.Type = value; }
    }
}

从外键相关表中加载字段作为本机类型

1 个答案: