Generate Unique Key PHP & MySql

generatekey.php

<?php

// Koneksi
$host	= "localhost";
$user	= "root";
$pass	= "";
$db	= "db_generate";
$mysqli = new mysqli($host, $user, $pass, $db);

// Generate Key

$ceksama=TRUE;
while($ceksama==TRUE){
  $query_generate = $mysqli->query("SELECT LEFT(MD5(NOW()), 8) as kunci");
  $data = mysqli_fetch_array($query_generate);
  $key = $data['kunci'];

  $query_cek = $mysqli->query("SELECT unique_key FROM tbl_key WHERE unique_key='$key'");
  $cekdata = mysqli_num_rows($query_cek);

  // Cek Jika Key Sudah Ada Di dalam Tabel
  if($cekdata > 0){
      $ceksama = TRUE;
      echo "Key Sudah Ada, Ulang Lagi <br>";
  }else{
  	$ceksama = FALSE;

  	// insert Key kedalam Tabel
  	$insert = $mysqli->query("INSERT INTO tbl_key SET unique_key='$key'");
  	if($insert){
  		echo "Key Belum Ada, Insert Berhasil dengan key <strong> $key </strong>";	
  	}else{
  		echo "Insert Gagal, Silahkan Periksa Coding Anda";	
  	}
  }
}
    
?>