DELETE from item
where item_code in (
 select i.item_code from item as i
 join stock as s on i.item_code = s.item_code
 where i.STOCK_MANAGEMENT_TYPE = '1'
 AND LAST_DELIVERY_DATE IS NOT NULL
 group by i.item_code
 HAVING MAX(s.LAST_DELIVERY_DATE) <= DATE('2023-06-01', '-6 months')
 and sum(s.ACTUAL_AMT) = 0
)
or item_code not in (select s.item_code from stock s)
and item.STOCK_MANAGEMENT_TYPE = '1'