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 )
)