PHP and Mysql check if selected row is last -

i have been trying check if selected row last in mysql data records, if last go first record. here have done far:

$fps = @fopen('number.txt', "r+"); $somay =  fread($fps, filesize('number.txt'));  fclose($fps);   $num = ($somay+1); $file = "number.txt";    $fh = fopen($file,'w+') or die("cant open file"); fwrite($fh,$num); fclose($fh);  $sql = "select @last_id := max(id),token `token` `id` = '".$somay."'";  if (!$result = $mysqli->query($sql)) {     echo "sorry, website experiencing problems.";     echo "error: our query failed execute , here why: \n";     echo "query: " . $sql . "\n";     echo "errno: " . $mysqli->errno . "\n";     echo "error: " . $mysqli->error . "\n";     exit; } if ($result->num_rows === 0) {     echo "we not find match id, sorry that. please try again.";     exit; }  while ($tokennek = $result->fetch_assoc()) { $token = $tokennek[token]; $tokenid = $tokennek[last_id]; } if($somay == $tokenid){ $file = "number.txt";    $fh = fopen($file,'w+') or die("cant open file"); fwrite($fh,1); fclose($fh); } 

let me make more clear here doing saving file named number.txt keep record of token been used , go next token/row.