A dependent entity cannot exist without its principal entity. In a book catalog, Rating depends on Book, while Book can exist without a rating. EF Core uses navigation properties and foreign-key conventions to map the relationship. section 5.2.3
Listing 5.8 One-to-one relationship with Book as the parent and Rating as the child
class Book {
public int Id {get;set;}
public Rating? Rating {get;}
}
class Rating
{
public int Id {get;set;}
public int BookId {get;set;}
public Book Book {get;set}
}
This C# model shows Book as the principal and Rating as the dependent, linked by BookId. section 5.2.3
