select * from ITEM as t2
    left join STOCK on STOCK.ITEM_CODE = t2.ITEM_CODE
    where
    (
        (LAST_DELIVERY_DATE<datetime('2023-06-01', '-6 months') and ACTUAL_AMT = 0) or
        (LAST_DELIVERY_DATE is null and SALE_START_DATE <datetime('2023-06-01', '-6 months')) or
        (STOCK.ITEM_CODE is null)
    )
    and  t2.STOCK_MANAGEMENT_TYPE = 1