在实体框架中用不同的名称两次映射外键

Question

I have a MasterConfig table, where I want to store my values in CodeValue format. ie

ID   CODE            VALUE
1.   BusinessType    IT
2.   BusinessType    Marketing
3.   ContractType    General
4.   ContractType    Custom

So, to get records based on CODE field. eg. getCodeValue/ContractType

Now, I have a Contract table where I have to map these fields as Foreign Keys. My contract model looks like:

public class Contract
{
   [Key]
   public int ID{get; set;}
   public string Name{get; set;}

   [ForeignKey("CodeValue")]
   public int BusinessTypeID{get; set;}

   [ForeignKey("CodeValue")]
   public int ContractTypeID{get; set;}

   public virtual CodeValue CodeValue {get; set;}
}

While creating Controller with view, I get error that "Unable to retrieve metadata for Contract Model. Not able to map the fields".

Please suggest me a solution for this Master Config relation in Entity Framework (ASP.NET MVC) ?

Answer 1

It needs to map against a navigation property in the Contract class, something like this:

public class Contract
{
   [Key]
   public int ID { get; set; }
   public string Name { get; set; }

   [ForeignKey("BusinessType")]
   public int BusinessTypeID { get; set; }

   [ForeignKey("ContractType")]
   public int ContractTypeID { get; set; }

   public virtual CodeValue BusinessType { get; set; }
   public virtual CodeValue ContractType { get; set; }
}