Question

I have a Template class

public class Template
{
    public int Id { get; set; }
    public string Name { get; set; }
    public virtual ICollection<Category> Categories { get; set; }
    public virtual Template RelatedTemplate { get; set; }
    public virtual Field RelatedTemplatePrimaryField { get; set; }
    public virtual ICollection<Field> Fields { get; set; }
}

And a Field class

public class Field
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int Min { get; set; }
    public int Max { get; set; }
    public bool AllowEmpty { get; set; }
    public bool IsCollection { get; set; }
    public virtual ICollection<Template> Templates { get; set; }
}

The problem is it’s not creating a many to many relationship, it just adds a FK on the fields table, I want a many to many relationship on

Fields ICollection<Field> Fields

and

ICollection<Template> Templates

EDIT:
If I remove

public virtual Template RelatedTemplate { get; set; }
public virtual Field RelatedTemplatePrimaryField { get; set; }

It works… Any ideas?

Answer 1

This is a case where you must help EF to correctly recognize your relations. You can do it either by data annotations:

[InverseProperty("Fields")]
public virtual ICollection<Template> Templates { get; set; }

or by fluent-API:

modelBuilder.Entity<Template>()
            .HasMany(t => t.Fields)
            .WithMany(f => f.Templates);