无法使用Jquery显示JSON格式的数据库结果

I have Codeigniter application which fetches data from database as result array, converts data to Json and displays the results. However I keep getting undefined as display result.

Model

 $this->db->where('product_name',$sid);
      //  $this->db->select('product_title');
        $res = $this->db->get('products');
         $data = $res->result_array();  
         return $data;

View:

<script language="javascript">
    $('#findsubmit').click(function() {
        $.get("/products/index.php/find/lookup",{id : $('#id').val() },function(data) {

            $('#result').html('Product name: ' + data.product_name);
            //+ ' Last name: ' + data.lastname);
        },"json");
        return false;
});
</script>

Resulting array I receive in Firebug:

[{"category":"camera","product_name":"Sony HX20"},{"category":"camera","product_name":"Canon SZ220"}]

If I create simple array like this all works fine:

return array('category' => 'camera','product_name' => 'Sony HX20');

Resulting array I receive in Firebug:

{"category":"camera","product_name":"Sony HX20"}

In your JSON data, you receive an array of several results: data.product_name is not defined, but data[0].product_name and data[1].production_name are.

You should try to either return only one result (like the one you build manually), or iterate on data.

Edit: here's a sample on how to use $.each:

var names = 'Product name: ';
$.each(data, function(index, element) {
    if (index > 0) {names += '; ';}
    names += element.product_name;
});
$('#result').html(names);