php - Why does my echo not work given no results found? -

i performing routine check if books exist in database given range. want echo if no books found. have following:

$search = mysqli_query($con,$query);  while(list($book_id, $title, $authors, $description, $price) = mysqli_fetch_row($search)){  if(!empty($book_id)) {  echo "book id: " . $book_id . "<br/>"; echo "book title: " . $title . "<br/>"; echo "authors: " . $authors . "<br/>"; echo "description: " . $description . "<br/>"; echo "price: " . $price . "<br/>"; echo "<br/>";  }  if(empty($book_id)){     echo "fail";     } } 

if no books found nothing printed. echo not work? how come?

thanks

because if no records returned, won't enter in while @ all, $book_is contain value false , while(false)... know

in situation may use mysqli_num_rows check if there rows found