How to configure a One-to-Many relationship in EF

Question

I have the following model

public class PageConfig : Base
{
    // Properties Etc..

    public ICollection ScrollerImages { get; set; }
}
         


        

Answer 1

If you want to create an one-to-many relationship between those two entities your model would be like this:

public class PageConfig
{
    public int Id {get;set;}

    //navigation property
    public ICollection ScrollerImages {get;set;}
}

public class Image 
{
    public int Id {get;set;}

    //FK
    public int? PageConfigId {get;set;}

    //navigation property
    public PageConfig PageConfig {get;set;}
}

And the Fluent Api configuration would be:

modelBuilder.Entity()
            .HasOptional(i=>i.PageConfig)
            .WithMany(pc=>pc.ScrollerImages)
            .HasForeignKey(i=> i.PageConfigId);

If you idea is create an unidirectional one-to-many relationship then delete the FK and the navigation property on Image entity and configure the relationship this way:

modelBuilder.Entity()
            .HasMany(pc => pc.ScrollerImages)
            .WithOptional();

Check this link for more info about this kind of relationship