public List <Book> BookGetSortedAndFiltered(string sortColumn, string sortColumnDir, string searchValue, int skip = 0, int take = 0)
        {
            BookDAL dal = new BookDAL(_connection);

            if (0 == take)
            {
                take = dal.BooksObtainCount();
            }
            return(dal.BookGetSortedAndFiltered(sortColumn, sortColumnDir, searchValue, skip, take));
        }