entity-framework - 如何发布到 odata webapi 中的相关集合

Question

我找到了这个 answer这帮助我设置了路线，但我在将实体添加到相关集合时遇到了问题。

模型:

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; }
}

发布到相关集合的 Controller 方法:

    [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);
    }

我可以看到 Author 已发送，但 book.Authors 为 null，您无法添加。 link to image

Answer 1

寻找不会​​带回 child 。尝试:

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

Load related entities