select TO_NUMBER(ZSLXDBH) from PAYMENT_ITEM_HIS where rownum = 1 and ZSLXDBH is not null and trim(TRANSLATE(ZSLXDBH,'0123456789',' ')) is null order by TO_NUMBER(ZSLXDBH) desc
from PaymentItemHis t where t.zslxdbh is not null and trim(TRANSLATE(t.zslxdbh,'0123456789',' ')) is null order by TO_NUMBER(t.zslxdbh) desc