mysqli - number of rows in database - prepared statements - php -

i can't seem work out how retrieve number of rows database using query, whenever run query returns 0 though it's in database

$username = $_post['username']; $hash = password_verify($password, $passwordcheck);  if($stmt = $conn -> prepare("select username, email, password users (username = ? or email = ?) , password = ?")) {      $stmt -> bind_param("sss", $username, $username, $hash);     $stmt -> execute();      $stmt -> bind_result($checkedusername, $checkedemail, $checkedpassword);      $stmt -> fetch();     $numberofrows = $stmt->num_rows;      $stmt -> close(); } echo '# rows: '.$numberofrows; 

can give me hints? can't see wrap head around it, thanks.

btw, $hash has been queried prior statement.

posting community wiki:

add $stmt->store_result(); after execute()