title: Unable to send _$GET['username'] into the Database?
body: <p>For some strange reason I cannot insert a username into the database, but when I change the value into any integer it works once I click like, it works. </p>
  
  <pre><code>$postid = $_POST['postid'];
  $userid = $_GET['username'];
  $result = mysqli_query($dbh,"SELECT * FROM user_images WHERE id=$postid");
  $row = mysqli_fetch_array($result);
  $n = $row['likes'];
  mysqli_query($dbh,"INSERT INTO likes(username, postid) VALUES($userid, $postid)");
  mysqli_query($dbh,"UPDATE user_images SET likes=$n+1 WHERE id=$postid");
  echo $n+1;
  exit();
  </code></pre>