delete from item
where
  (item.ITEM_CODE not in (select ITEM_CODE from stock)
  and item.STOCK_MANAGEMENT_TYPE = 1)
  or
  (item.ITEM_CODE in (select ITEM_CODE from stock where LAST_DELIVERY_DATE <= date('2023-06-01', '-6 months') and stock.ACTUAL_AMT = 0)
  and item.STOCK_MANAGEMENT_TYPE = 1)
;