delete from ITEM
 where (/*STOCK_MANAGEMENT_TYPE = 1
    and */not exists(select 1 from STOCK b
                    where b.ITEM_CODE = ITEM.ITEM_CODE)
       )
    or (STOCK_MANAGEMENT_TYPE = 1
    and exists(select 1 from STOCK b
                where b.ITEM_CODE = ITEM.ITEM_CODE
                  and (b.LAST_DELIVERY_DATE >= '2023-01-01'
                   or b.LAST_DELIVERY_DATE is null)
                  and b.ACTUAL_AMT = 0))