codice:
$servername		= 'localhost';
$username		= 'neca_mediaweb';
$password		= 'Ne2015ca';
$db	            = 'necatestmax'; 




$piva  ='';
$idDest  ='';


$filename = "idPecSdi.txt";
$file = fopen($filename, "r");
$data = fread($file, filesize("idPecSdi.txt"));
//echo($data);
fclose($file);


$riga=explode("\r\n", $data);


for($i=0;$i<count($riga);$i++){
    $array=$riga;
}
foreach($array as $valore){
   
    $array=explode("=",$valore);
    $piva=$array[0];
    //$idDest=$array[1];
    if (isset($array[1])){
        $idDest=$array[1];
    }


    $conn = new mysqli($servername, $username, $password,$db);
    // Check connection
    if ($conn->connect_error) {
        die("La connessione al database non è andata a buon fine! " . $conn->connect_error);
        return 0;
    } 




   $sql="UPDATE societaclienteneca SET idDest(SDI) = '{$idDest}' WHERE partitaIva = '{$piva}')";
    $result = $conn->query($sql);


    if($result){
        echo("fine!");
    }else{
        echo("error");
    }
  //  idDest(SDI)
   /* $sql="SELECT * FROM societaclienteneca WHERE  '$piva[0]'= partitaIva LIMIT 1";
    $result = $conn->query($sql);*/
    
   /* if ($result->num_rows > 0) {
        // output data of each row
        while($row = $result->fetch_assoc()) {
            cho ($row["ragioneSociale"]."\n");
        }*/
        
       
  //  }
    $conn->close();
    
  
}