Oracle°üÄÚÊý¾Ý¹ý³ÌµÄÎÊÌâ

SQL code:
procedure sc_numberbiao(use_sno char, use_number char) is
have number; --ÓÃÓÚÈ·¶¨ÊÇ·ñ´æÔÚ±íSC_NUMBER
cnumber number; --ÒÑÓпγÌÊýÁ¿
excp_number exception; --×Ô¶¨ÒåÒì³££¬ÓÃÓÚÈ·ÈÏÓû§Ñ¡¿ÎÊìÁ·ÊÇ·ñ´ïµ½ÒÑÓпγÌÉÏÏÞ
begin
select count(*) into cnumber from course ;
if use_number > cnumber or use_number < 0 then
raise excp_number;
end if;
select count(*) into have from user_tables where table_name = 'SC_NUMBER';
if have <> 0 then
execute immediate 'update sc_number set cnonumber = use_number where sno = use_sno';
if sql%rowcount = 0 then
execute immediate 'insert into sc_number values (trim(use_sno), trim(use_number))';
dbms_output.put_line('²åÈëѧºÅΪ' || use_sno || 'µÄѧÉúÑ¡¿ÎÃÅÊýΪ' ||
use_number);
else
dbms_output.put_line('¸üÐÂѧºÅΪ' || use_sno || 'µÄѧÉúÑ¡¿ÎÃÅÊýΪ' ||
use_number);
end if;
else
execute immediate 'create table sc_number(sno char(20),cnonumber char(3))';
execute immediate 'insert into sc_number values (trim(use_sno), trim(use_number))';
dbms_output.put_line('½¨±ísc_number²¢ÇÒ²åÈëѧºÅΪ' || use_sno || 'µÄѧÉúÑ¡¿ÎÃÅÊýΪ' ||
use_number);
end if;
commit;
exception
when excp_number then