Entity Framework 6 One-Way relationship using Code First -

i have following scenario:

1. color class

   public int id {     get;     set; }  public string name {     get;     set; }  public string hex {     get;     set; } 

2. widget class

   public int id {     get;     set; }  public int headerbackgroundcolorid {     get;     set; }  public color headerbackgroundcolor {     get;     set; } 

using code-first, trying create one-way relationship between widget color classes headerbackgroundcolor / headerbackgroundcolorid fields.

normally in config class:

this.hasoptional(r => r.headerbackgroundcolor )     .withmany(m => m.widgets)     .hasforeignkey(fk => fk.headerbackgroundcolorid); 

but not intrested in adding widgets collection color class. tried this:

this.hasoptional(r => r.headerbackgroundcolor )     .withmany()     .hasforeignkey(fk => fk.headerbackgroundcolorid); 

but throws validation error.

what's way right?

you getting error because headerbackgroundcolorid non-nullable int, cannot optional.

all need achieve you're looking turn foreign key nullable int...

public int? headerbackgroundcolorid { get; set; } 

because named foreign key match navigation property (headbackgroundcolorid , headerbackgroundcolor) follows code first conventions, not need create explicit mappings. making above change make relationship optional.