无法将本地存储上载到数据库

I have some data that I want to store in Database for synchronization. Here is my jQuery code:

$(document).ready(function() {

  var local_array = [];

  for ( var i = 0, len = localStorage.length; i < len; ++i ) {
    local_array.push(localStorage.key(i));
    local_array.push(localStorage.getItem(localStorage.key(i)));
    console.log(local_array);
  } 

  $.ajax({
    type: "POST",
    url: "uploadtodatabase.php",
    data: {data: local_array}
  });
});

This is my PHP code:

  <?php session_start();
  $connection = new mysqli('host', 'name', 'password', 'database');
  $username   = $_SESSION['user'];
  $username   = $connection->real_escape_string($username);
  $query      = $connection->query("SELECT * from members WHERE username ='$username'");
  $matches    = mysqli_num_rows($query);

  if ($matches == 1) {
  $row     = mysqli_fetch_array($query);
  $visited = $_POST['data'];
  $visited = $connection->real_escape_string($visited);
  $connection->query("UPDATE members SET visited = '$visited' WHERE username ='$username'");
  } 

  mysqli_close($connection);
  ?>

The data is stored in local_array , as I checked in console. The jQuery code in is footer.php. This is the same location where I store uploadtodatabase.php. However, footer.php is appended to other files which might not be in same directory. Can this cause the problem? I have never used AJAX before. So, I might be doing something stupid and not notice it at all.

Hi you are half way there, you just need to decode the array inside of your php code...

if(!empty($_POST['data'])) {
    $data = explode(',',$_POST['data']);
    //code to store $data content
}

now you can use the $data variable to store the contents of the session from localSotrage