DELETE FROM ITEM 
WHERE
STOCK_MANAGEMENT_TYPE = '1'
AND
(NOT EXISTS 
    (SELECT B.ITEM_CODE 
    FROM STOCK B
    WHERE ITEM.ITEM_CODE = B.ITEM_CODE)
OR EXISTS 
    (SELECT B.ITEM_CODE 
    FROM STOCK B 
    WHERE ITEM.ITEM_CODE = B.ITEM_CODE 
    GROUP BY B.ITEM_CODE 
    HAVING MAX(IFNULL(B.LAST_DELIVERY_DATE, '2999-12-31')) <= DATE('2023-06-01', '-6 months') 
    AND SUM(B.ACTUAL_AMT) = 0)
)
;