How to post to a related collection in odata webapi

Question

I've found this answer which helped me to set a route, but I'm having a problem adding entity to a related collection.

Models:

public class Book
{
    public int BookId { get; set; }
    public string Title { get; set; } and so on

    [ForeignKey("AuthorId")]
    public ICollection<Author> Authors { get; set; }
}

public class Author
{
    public int AuthorId { get; set; }
    public string Name { get; set; }

    [ForeignKey("BookId")] 
    public ICollection<Book> Books { get; set; }
}

Controller method for posting to a related collection:

    [ODataRoute("Books({key})/Authors")]
    public async Task<IHttpActionResult> PostAuthor([FromODataUri] int key, Author author)
    {
        var book = await db.Books.FindAsync(key);
        if (book == null)
        {
            return NotFound();
        }
        book.Authors.Add(author);

        await db.SaveChangesAsync();
        return StatusCode(HttpStatusCode.NoContent);
    }

I can see that Author is sent through, but book.Authors is null and you can't add to it. link to image

Steve Greene · Accepted Answer · 2016-05-23T15:15:45.210

1

Find won't bring back children. Try:

var book = await db.Books
                    .Include(b => b.Authors)
                    .FirstOrDefaultAsync(b => b.BookId == key);

Load related entities

edited May 23 '16 at 15:15

answered May 23 '16 at 14:22

Steve Greene

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Yes, sorry had a typo - you don't need a Where() when using FirstOrDefault. – Steve Greene May 23 '16 at 15:10
I edited your answer with my sollution so that I can accept it. Your anwer was the closest to answering it, but it gave an error in VS. – kolbanis May 23 '16 at 15:15

How to post to a related collection in odata webapi

1 Answers1