public IHttpActionResult Add(Book Model) { try { if (!ModelState.IsValid) { return(BadRequest("Data can not be saved")); } BookCategory _category = _bookCategoryRepository.Get(Model.CategoryId); if (_category == null) { return(NotFound()); } if (_bookRepository.AlreadyExists(Model.ISBN)) { return(BadRequest("ISBN already assigned to a book")); } string _message; if (!_bookRepository.ValidateInput(Model, out _message)) { return(BadRequest(_message)); } _bookRepository.Add(Model); _bookRepository.Save(); return(Ok("Record Saved")); } catch (Exception) { return(BadRequest("Record can not be saved")); } }