DELETE FROM ITEM
WHERE
 ( (ITEM_CODE NOT IN (SELECT ITEM_CODE FROM STOCK))
  OR
  (ITEM_CODE IN
    (
        SELECT ITEM_CODE FROM STOCK
        GROUP BY ITEM_CODE
        HAVING MAX(LAST_DELIVERY_DATE) <= DATE('2023-06-01', '-6 months') AND SUM(ACTUAL_AMT) = 0
    )
  )
 ) AND STOCK_MANAGEMENT_TYPE = 1