Showing more columns in backend in orders and customers

[v00d0]

Hi everybody, i'm trying to show in customers list (back office) a column with the groups where single customer is linked to and in orders list the vendor releated to the single product that has been sold.

 

For customers i tried to add a select at the bottom of this query but nothing show up in the list. For orders i do not know from where to start.

$this->_select = '
a.date_add, gl.name as title, (
SELECT SUM(total_paid_real / conversion_rate) FROM '._DB_PREFIX_.'orders o
WHERE o.id_customer = a.id_customer
'.Shop::addSqlRestriction(Shop::SHARE_ORDER, 'o').'
AND a.active = 1
) as total_spent, (
SELECT c.date_add FROM '._DB_PREFIX_.'guest g
LEFT JOIN '._DB_PREFIX_.'connections c ON c.id_guest = g.id_guest
WHERE g.id_customer = a.id_customer
ORDER BY c.date_add DESC
LIMIT 1
) as connect,
(SELECT GROUP_CONCAT(cg.id_group SEPARATOR ", ") FROM '._DB_PREFIX_.'customer_group cg WHERE cg.id_customer = a.id_customer GROUP BY cg.id_customer)';

i'm really newbie with prestashop i started to use it yestarday.

 

many thanks