RPAD(str,len,padstr)

返回字符串str，右填充以字符串str中墊到len字符長度。如果str為大於len，返回值被縮短至len個字符。

SQL> SELECT RPAD('hi',5,'?');
+---------------------------------------------------------+
| RPAD('hi',5,'?')                                        |
+---------------------------------------------------------+
| hi???                                                   |
+---------------------------------------------------------+
1 row in set (0.00 sec)