delete from ITEM
 where STOCK_MANAGEMENT_TYPE = 1 
   and (not exists (select S1.ITEM_CODE from STOCK S1 where S1.ITEM_CODE = ITEM_CODE)
         or exists(select S2.ITEM_CODE from STOCK S2 
                           where S2.ITEM_CODE = ITEM_CODE
                           group by S2.ITEM_CODE
                          having MAX(IFNULL(S2.LAST_DELIVERY_DATE, '2999-12-31')) <= DATE('2023-06-01', '-6 months')
                             and SUM(S2.ACTUAL_AMT) = 0))
;