delete from ITEM
where 
STOCK_MANAGEMENT_TYPE = 1
and
not exists (select ITEM_CODE from STOCK where ITEM.ITEM_CODE = STOCK.ITEM_CODE) 
or exists (select ITEM_CODE from STOCK 
        where ITEM.ITEM_CODE =STOCK.ITEM_CODE 
        group by ITEM_CODE
        having max(ifnull(LAST_DELIVERY_DATE,'9999-00-00')) <= date('2023-06-01', '-6 months') and sum(ACTUAL_AMT) = 0)
;