2、	編寫一個過程模擬到讀書室刷卡借書。要求有一個IN參數和一個OUT參數。IN參數用于接受傳遞過來的借書證條碼，然后在表中檢索有無讀者，如有則將該讀者的名稱賦給OUT參數。如沒有則提示“沒有找到該讀者信息”。
Create table tab_liab
(num_card char(8),
sname varchar2(20))
insert into tab_liab values(‘001’,’zhou’);
上述表已經創建，只需針對此表編寫即可。

Create table tab_liab(
num_card char(8),
sname varchar2(20)
);

insert into tab_liab values('001','zhou');

create or replace procedure find_reader
(i_num_card in char,o_sname out varchar2)
as
countstudent integer;
var_sname tab_liab.sname%type;
begin
  select count(*) into countstudent from tab_liab where i_num_card=num_card;
  if countstudent=0 then
	dbms_output.put_line('沒有找到讀者信息');
  else
	select sname into var_sname from tab_liab where i_num_card=num_card;
	dbms_output.put_line(var_sname);
  end if;
end find_reader;

declare
var_studentname varchar2(20);
begin
find_reader('002',var_studentname);
end;