oracle存储过程中写IF ELES

用，这些都是成对出现的，例如：
if a is not null or b != '01' then
......    
elsif (b =1 or b=2) and a is null then
    if b=1 then
    ......
    end if;
......

end if;

create or replace procedure update_ply_base_status is
vOrderId TB_TSWWW_PLY.C_ORDERID_RELATE%TYPE;
vProdNo  TB_TSWWW_PLY.c_Prod_No%TYPE;
vFinS    TB_TSWWW_PLY.c_Fin_Stat%TYPE;
vState    TB_TSWWW_PLY.c_Stat%TYPE;

CURSOR CUR_EDR IS
   select t.c_orderid_relate,
   t.c_prod_no,
   t.c_fin_stat,
   t.c_stat
   from TB_TSWWW_PLY t where t.t_crt_date>=sysdate-1/24 or t.t_upd_date>=sysdate-1/24;

BEGIN

  BEGIN
    OPEN CUR_EDR;
    LOOP
      FETCH CUR_EDR
        INTO vOrderId, vProdNo, vFinS, vState;
      EXIT WHEN CUR_EDR%NOTFOUND;

      IF vFinS='0' and vState='1' THEN
         BEGIN
             IF  substr(vOrderId,0,2)='00' THEN
               
                    update t_ply_base a set a.c_order_status='005' where a.c_orderid_relate=vOrderId;
                
              ELSE
              
                    update t_ply_base a set a.c_order_status='005'  where a.c_orderid_relate=vOrderId and a.c_prod_no=vProdNo;

             END IF;
         END;

      END IF;

      IF vFinS='1' and vState='1' THEN
         BEGIN
             IF  substr(vOrderId,0,2)='00' THEN
                 
                    update t_ply_base a set a.c_order_status='008',a.c_payment_status='1' where a.c_orderid_relate=vOrderId;
                
             ELSE
                
                   update t_ply_base a set a.c_order_status='008',a.c_payment_status='1' where a.c_orderid_relate=vOrderId and a.c_prod_no=vProdNo;
             
             END IF;
         END;

      END IF;

          END LOOP;
      CLOSE CUR_EDR;
    COMMIT;
  END;

end update_ply_base_status;