GetBooks.cs

[HttpGet]
        public async Task<IActionResult> GetBooks()
        {
            List<BookInfoDto> books = await _db.Books
                .Select(x => new BookInfoDto() { BookID = x.BookID, Name = x.Name, AuthorName = x.Author.Name })
                .ToListAsync();

            if (books.Count() == 0)
                return NotFound();

            return Ok(books);
        }