php - Prepare not defined

Question

I have tried setting sessions which are stored in database.I have achieved this through implementing SessionHandlerInterface class.However i havenot used prepared statements before but now i want to implement prepared statements in order to make it sql injection proof.However , when i try the prepare method it shows me an error

Method Prepare not defined in Class

i even tried extending mysqli_stmt class which contains the methods for prepared statements.

This is the full code of session class that stores sessions inside the database.

http://codepad.org/KmLtO9ym

Part of the code to make the question much more clear

class SysSession implements SessionHandlerInterface
{
   private $link;

public function open($savePath, $sessionName)
{
    $link = new mysqli("localhost","root","","cakenbake");
    if($link){
        $this->link = $link;
        return true;
    }else{
        return false;
    }
}
public function close()
{
    mysqli_close($this->link);
    return true;
}
public function read($id)
{


    $result = mysqli_query($this->link,"SELECT Session_Data FROM Session WHERE Session_Id = '".$id."' AND Session_Expires > '".date('Y-m-d H:i:s')."'");

    /*$result=$this->link->prepare("Some query inside")
     * This shows up an error stating prepare method not found
     *
     */

    if($row = mysqli_fetch_assoc($result)){
        return $row['Session_Data'];
    }else{
        return "";
    }
}

Answer 1

The problem was with my IDE.It was the one who was showing errors.Restarted my IDE and it worked fine.