[Oracle] 循环的几种方式

-- goto
declare
   x number;
begin
   x:=9;
   <<repeat_loop>>
   x:=x-1;
   dbms_output.put_line('x: '||x);
   if x>0 then
     goto repeat_loop;
   end if;
end;

-- for
declare
   x number;
begin
   x:=1;
   for x in reverse 1..10 loop
     dbms_output.put_line('x: '||x);
   end loop;
   dbms_output.put_line('end loop x: '||x);
end;

-- while
declare
   x number;
begin
   x:=0;
   while x < 10 loop
      dbms_output.put_line('x: '||x);
      x:=x+1;
   end loop;
   dbms_output.put_line('end while:x '||x);
end;

-- loop
declare 
   x number;
begin
   x:=0;
   loop
      x:=x+1;
   exit when x>9;
   dbms_output.put_line('x: '||x);
   end loop;
   dbms_output.put_line('end loop x: '||x);
end;

参考：
http://blog.sina.com.cn/s/blog_710faf420100zc6v.html