EF代码优先-如何为不同类型的父母使用的子对象表指定外键名称

Question

I've got some objects that look like this:

abstract public class Field
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Ordinal { get; set; }
}

[Table("DropDownField")]
public class DropDownField : Field
{
    public virtual List<FieldOption> Options { get; set; }
}

[Table("RadioButtonField")]
public class RadioButtonField : Field
{
    public virtual List<FieldOption> Options { get; set; }
}

public class FieldOption
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Value { get; set; }
}

In my database, it ends up creating the a FieldOptions table using Code First. However, it creates the following columns:

• Id
• Name
• Value
• DropDownField_Id
• RadioButtonField_Id

What I'd like to see is just one Field_Id in this table since the Id of a field has to be unique across the different types of fields.

Is there a way to do this? I've done some searching but I must not know the right search terms to use to find the answer.

Answer 1

imho, what you want, from a relational database point of view, is a column (Option.FieldId) being a foreign key to 2 tables DropDownField and RadioButtonField.

That is whenever you insert an option, FieldId must reference an existing DropDownField AND an existing RadioButtonField.

That is at least weird.

I don't think this can/should be achieved.