Entity Framework InverseProperty
The InverseProperty attribute is used to denote the inverse navigation property of a relationship when the same type takes part in multiple relationships.
- It is used when you need to indicate that navigation property in one class is related to the same foreign key as another navigation property in another class.
- For example, in the
Bookclass, you may want to keep track of who wrote a book as well as who edited it.
In the following example, we have added two new navigation properties for the 'Author' class.
public class Book { public int BookId { get; set; } public string Title { get; set; } public Author CreatedBy { get; set; } public Author UpdatedBy { get; set; } }
The Author class has navigation properties back to the Book class, one for all of the books written by the author and one for all of the books updated by that author.
public class Author { public int AuthorId { get; set; } public string Name { get; set; } public virtual ICollection<Book> BooksWritten { get; set; } public virtual ICollection<Book> BooksUpdated { get; set; } }
The InverseProperty attribute is applied to the navigation properties in the Author class to specify their corresponding inverse navigation properties in the Book class.
public class Book { public int BookId { get; set; } public string Title { get; set; } public Author CreatedBy { get; set; } public Author UpdatedBy { get; set; } } public class Author { public int AuthorId { get; set; } public string Name { get; set; } [InverseProperty("CreatedBy")] public virtual ICollection<Book> BooksWritten { get; set; } [InverseProperty("UpdatedBy")] public virtual ICollection<Book> BooksUpdated { get; set; } }
