Problems creating a Foreign-Key relationship on Entity Framework

Question

i\'m having trouble configuring a foreign key relationship in my Entity Framework fluent Api:

Here is the head of the report:

 public class Testata
{         


        

Answer 1

There is a conflict between your foreign key property in class Dettaglio...

public virtual int IDTEST { get; set; }

...which has a non-nullable type (int) and therefore cannot be optional and your mapping...

this.HasOptional(t => t.TEST_TABLE) //...

...where you want the relationship to be optional.

If you indeed want an optional relationship use a nullable FK property:

public virtual int? IDTEST { get; set; }

Otherwise you must use HasRequired for a required relationship with a non-nullable FK property.