暂时还只看到两种，先放在这里。如果以后有再更新^_^

方式1:当你确定知道要做多少次循环的时候

FOR loop_index IN 1..100

LOOP ...

END LOOP;

方式2:

FOR loop_index IN cursor_name

LOOP...

END LOOP;

例子:

SQL> set serveroutput on
SQL> l
1 DECLARE
2 CURSOR cur_user IS
3 select employeeid, firstname, lastname from users;
4 Begin
5 For l_cur IN cur_user
6 LOOP
7 DBMS_OUTPUT.PUT_LINE(cur_user%ROWCOUNT || ':'||l_cur.employeeid||' '||l_cur.firstname);
8 END LOOP;
9* END;

（中间结果省略）
PL/SQL procedure successfully completed.

发现一种更加神奇的cursor用法，不过严格来说跟loop没啥关系。但是还是可以放在这里:

BEGIN
For l_cur IN (select employeeid, firstname, lastname from users)
LOOP
DBMS_OUTPUT.PUT_LINE(l_cur.employeeid||' '||l_cur.firstname);
END LOOP;
END;