delete 
from item
where STOCK_MANAGEMENT_TYPE=1
and   (
        not exists (select item_code from stock where stock.item_code=item.item_code)
        )
or    (
        exists (select item_code from stock where stock.item_code=item.item_code
                    group by item_code having max(ifnull(LAST_DELIVERY_DATE,'2999-12-31')) <=date('2023-06-01','-6 months')
                                                and sum(actual_amt)=0
                )
        );