I have tried looking for answers and though I am sure my question has been answered somewhere, I failed to get the answer. 
I have two tables independent but related. I am dealing with my classes in EF.
I want to create a model in c# with none or one to many relationship.
How do I do that in code?
Below are my two models:

```
public class adult
{
        [Key]
    public int ID { get; set; }
    [StringLength(50, ErrorMessage = "{0} cannot exceed {1} characters")]
    public string LastName { get; set; }
    public string Initials { get; set; }
    public string Title { get; set;}
    public string Address1 {get; set;}
    public string Address2 {get; set;} 
 }

```

Below is the second model with many 'children'.

```
 public class children
{
    [Key]
    public int childNo { get; set; }
    public string favourite { get; set; }
    **public int childID { get; set; }**

    [Required]
    [StringLength(50, ErrorMessage = "{0} cannot exceed {1} characters")]
    public string colour { get; set; }
    public DateTime DateReceived { get; set; }
    public DateTime DatePaid { get; set; }
}

```

I am interested in a none or one to many relationship i.e I can have an adult without a child. 
The childID in the children class corresponds to the ID in adult class. We have none or one ID in class matching with many childID in the children class. How do I model this in my class? I am also interested in displaying those mapped values in one view and edit, create and save the changes.