delete 
from
    ITEM 
where
STOCK_MANAGEMENT_TYPE = 1
and
    ITEM_CODE in ( 
        select
            ITEM_CODE
        from
            ITEM 
        WHERE
           NOt EXISTS ( 
                SELECT
                    * 
                FROM
                    STOCK 
                WHERE
                    STOCK.ITEM_CODE = ITEM.ITEM_CODE
            )
    );