PHP / MySQL PDO Update statement problem...

[Hazukiy]

Hi, I'm trying to make it so the user can enter some text into a text box and from there it will add a link and NOT override it.

 

Here's my problem, I can't seem to get this statement to work correctly as I don't know how to put some kind of variable.

 

Overall: I want it so it adds what ever has been entered into the INPUT tag and add into the correct user_id

 

Please exuse my messy code, I'm just trying to get it to work before I tidy it up.

 

 

Declared variables at the top of the document:

class Users {
	 public $user_id = null;
	 public $username = null;
	 public $email = null;
	 public $password = null;
	 public $salt = "Zo4rU5Z1YyKJAASY0PT6EUg7BBYdlEhPaNLuxAwU8lqu1ElzHv0Ri7EM6irpx5w";
	 public $links = null;
	 
	 public function __construct( $data = array() ) {
		 if( isset( $data['user_id'] ) ) $this->user_id = stripslashes( strip_tags( $data['user_id'] ) );
		 if( isset( $data['username'] ) ) $this->username = stripslashes( strip_tags( $data['username'] ) );
		 if( isset( $data['email'] ) ) $this->email = stripslashes( strip_tags( $data['email'] ) );
		 if( isset( $data['password'] ) ) $this->password = stripslashes( strip_tags( $data['password'] ) );
		 if( isset( $data['links'] ) ) $this->links = stripslashes( strip_tags( $data['links'] ) );
	 }

Here's what I've made:

public function addLink() {
		$correct = false;
			try{
				$con = new PDO( DB_DSN, DB_USERNAME, DB_PASSWORD );
				$con->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
				$sql = "UPDATE  `a8906507_members`.`list_members` SET  `links` =  <SOME KIND OF VARIABLE HERE> WHERE  `list_members`.`user_id` = <SOME KIND OF VARIABLE HERE> LIMIT 1";

				$stmt = $con->prepare( $sql );
				$stmt->bindValue( "links", $this->links, PDO::PARAM_STR );
				$stmt->execute();
			}catch( PDOException $e ) {
				return $e->getMessage();
			}
	 }

Here's my HTML that connects to the public function and executes it.

<form action="" method="post" name="add_link" id="add_link"> 
	 <table border="0" id="table-add">
	  <th colspan="2">
	   <h1>Add a livestream</h1>
	   <?php if( !(isset( $_POST['add_link'] ) ) ) { ?>
	  <?php 
		} else {
			$usr = new Users;
			$usr->storeFormValues( $_POST );
			$errorMessage = "";
			$error = false;
			
			if( $usr->addLink() ) {
				echo 'Channel added!';
				$error = false;
			} 
			else {
				$errorMessage .= "<li class='error'>Link can't be added</li>";	
				$error = true;
			}
			
			if($error) 
			{
				echo($errorMessage);
			}
		}
	?>
	  </th>
	  <tr>
	   <td>
	    <p>Channel Name:</p>
       </td>
	   <td>
	    <input type="text" name="channel-name" class="frm-style" />
	   </td>
	  </tr>
	   <th colspan="2">
	   <input class="frm-submit-add" name="add_link" type="submit" value="Add" />
	   <th>
	  </tr>
	 </table>
	 </form>

Help will be appreciated, thanks.