Out of Area Postcodes

select count(*), postcode
from sales_order_delivery delivery
join sales_order on delivery.sales_order_id = sales_order.id
join sales_order_attribute service on sales_order.id = service.sales_order_id and service.name = 'service'
join sales_order_attribute courier on sales_order.id = courier.sales_order_id and courier.name = 'courier'
where sales_order.created_on > subdate(now(), INTERVAL 1 MONTH)
and courier.value = 'DHL'
and service.value like '%48%'
group by postcode
order by count(*) desc;