oracle导出数据到文件

create directory aaa as 'D:/dir';

 grant read,write on directory aaa to aaaaa;

declare
  handle utl_file.file_type;
  buf varchar2(30000);
  n_count number := 0;
  i number :=1;
  filename varchar2(32);
  c varchar2(1);
  cursor c_a 
  is 
    select  
    a.account_id, a.account, b.age, b.username
    from account_base a, account_ext b
    where a.account_id = b.account_id;
   v_a c_a%rowtype;
 
 
 begin
   filename := to_char(to_date('2012-01-01','yyyy-mm-dd')) || '_test.txt';
   handle :=utl_file.fopen('AAA',filename,'w', 50);
   buf := '';
 
  open c_a;
   loop
    fetch c_a into v_a;
    exit when c_a%notfound; 
    if(mod(i,500) = 499) then
    c := '';
    else
    c := chr(10);
    end if;
    buf :=buf || to_char(i) || '.'|| v_a.account_id||','||v_a.account|| ',' || v_a.age ||',' ||v_a.username || c; 
    i:=i +1; 
   if(mod(i,500) = 0) then
   
       utl_file.put(handle,buf);
       utl_file.new_line(handle);
       buf :=''; 
   dbms_output.put_line('aaaa');
   end if; 
   end loop;   
       utl_file.put(handle,buf);
       utl_file.new_line(handle);
 
   utl_file.fclose(handle);
 
 
 
 end;
 /