DELETE 
  FROM ITEM
 WHERE (NOT EXISTS (SELECT ITEM_CODE
                      FROM STOCK S
                     WHERE ITEM.ITEM_CODE = S.ITEM_CODE
                   )
         OR EXISTS (SELECT ITEM_CODE
                      FROM (SELECT ITEM_CODE, 
                                   MAX(S.LAST_DELIVERY_DATE) AS LAST_DELIVERY_DATE
                              FROM STOCK S
                             WHERE ACTUAL_AMT = 0
                             GROUP BY ITEM_CODE
                            )
                     WHERE ITEM.ITEM_CODE = ITEM_CODE 
                       AND LAST_DELIVERY_DATE < date('2023-06-01', 'localtime', '-6 month')
                     GROUP BY ITEM_CODE
                   )
       )
  AND ITEM.STOCK_MANAGEMENT_TYPE = 1;
  
  SELECT *
    FROM ITEM;