使用php循环更新mysql列

I need to update the initial values of a mysql column, a tokens column, at the beginning, those values are all null, then, they need to be updated, with a tokens generating function, how am doing it, it just doesn´t updates any values, see:

$query = "SELECT `id` FROM `acuses_recibo` WHERE `id_envio`=101 AND `token` IS NULL";
$result = mysqli_query($conn, $query);

here I select the id´s of those null tokens for an specific id_envio, then

while($row = mysqli_fetch_array($result, MYSQLI_ASSOC)){//as long as there are token null values
  foreach($row as $id=>$row['id']){
    $indice = $row['id'];
    $v=getToken(32);
    echo $v.PHP_EOL;
    echo "id es: ".$row['id'].PHP_EOL;
    $queryDos = "UPDATE `acuses_recibo` SET `token`={$v} WHERE `id`={$indice} ";
    mysqli_query($conn, $queryDos);
}

where getToken(32) calculates a token of length 32, this way no token is updated, the only way they get updated is if I set tokenin $queryDos to a fixed value, how could I remedy this in such a way that every token value gets updated? thanx i.a.

This is how I solved it, I separated the problem in two parts, the first just selects all the id´s for a specific id_envio as follows

$query = "SELECT `id` FROM `acuses_recibo` WHERE `id_envio`=101 AND `token` IS NULL";
$result = mysqli_query($conn, $query);
// an arrays is created and used to store the id´s selected
$members = array();
while($row = mysqli_fetch_array($result, MYSQLI_ASSOC)){
$members[] = array('id'=> $row['id']);
}
// the connection is then closed, something I found on mysql not being explicitly multiconnection
mysqli_close($conn);
// then a new connection is setup
$connDos = mysqli_connect($servername, $username, $password, $database);

Now, the token values are updated as follows, please note that $indice has to be cast to int type because the array fetched returns strings

foreach($members as $m){
  $indice = $m["id"];
  $indice = intval($indice);
  $voken=getToken(32);
  $queryDos = " UPDATE `acuses_recibo` SET `token`='{$voken}' WHERE   `id`='{$indice}' ";
  if (mysqli_query($connDos, $queryDos)) {
    echo "Record updated successfully".PHP_EOL;
  } else {
    echo "Error updating record: " . mysqli_error($connDos).PHP_EOL;
  }

}

then, the second connection is closed

mysqli_close($connDos);

and this is how I could update the token values to their calculated values. I hope it helps somebody.