[SOLVED]How to make a conditional insert in multiple tables?

[eluser]earlyriser[/eluser]
Now I got:

PHP Fatal error: Call to a member function on a non-object in /home/.../controllers/wine.php on line 49

whit the code

Code:

function comment_insert()
    {
        //check if the wine is in database
        $thename=$_POST['name'];
        $this->db->select('*');
        $this->db->from('wines');
        $this->db->where('name', $thename);
        $data['query']= $this->db->get();
        echo $query->num_rows();
    }