// Search from MySQL database table
$search=$_POST['search'];
$stat=$_POST['stat'];

$split = explode(" ", $search);

$query = $pdo->prepare("SELECT itemname, itemprice, itemupdate, itemstat, itemmarket, itemdiff FROM premium WHERE itemname LIKE ? AND itemname LIKE ? AND itemname LIKE ? AND itemname LIKE ? AND itemname LIKE ? AND itemname LIKE ? AND itemstat=? ORDER BY itemprice DESC LIMIT 15");
$query->bindValue(1, "%$split[0]%", PDO::PARAM_STR);
$query->bindValue(2, "%$split[1]", PDO::PARAM_STR);
$query->bindValue(3, "%$split[2]", PDO::PARAM_STR);
$query->bindValue(4, "%$split[3]", PDO::PARAM_STR);
$query->bindValue(5, "%$split[4]", PDO::PARAM_STR);
$query->bindValue(6, "%$split[5]", PDO::PARAM_STR);
$query->bindValue(7, $stat);
$query->execute();

SELECT * FROM premium WHERE itemname LIKE $split[0] and itemname LIKE $split[1] and itemname Like $split[2] ... and so on ...