MySQL ASCII码0-255

Question

在Python中，ord（）函数返回0到255之间的ASCII码：

>>> ord("a")
97
>>> ord("b")
98
>>> ord("c")
99
>>> ord("á")
225
>>> ord("í")
237
>>> ord("Ñ")
209

但是在MySQL中，即使使用charset修饰符，我也无法获得这些更高的代码：

mysql> SELECT ord("a"),ord("b"),ord("c");
+----------+----------+----------+
| ord("a") | ord("b") | ord("c") |
+----------+----------+----------+
|       97 |       98 |       99 |
+----------+----------+----------+

mysql> SELECT ord("á"),ord(_utf8"á"),ord(_utf8mb4"á"),ord(_latin1"á");
+-----------+----------------+-------------------+------------------+
| ord("á")  | ord(_utf8"á")  | ord(_utf8mb4"á")  | ord(_latin1"á")  |
+-----------+----------------+-------------------+------------------+
|     50081 |          50081 |             50081 |              195 |
+-----------+----------------+-------------------+------------------+

mysql> SELECT ascii("á"),ascii(_utf8"á"),ascii(_utf8mb4"á"),ascii(_latin1"á");
+-------------+------------------+---------------------+--------------------+
| ascii("á")  | ascii(_utf8"á")  | ascii(_utf8mb4"á")  | ascii(_latin1"á")  |
+-------------+------------------+---------------------+--------------------+
|         195 |              195 |                 195 |                195 |
+-------------+------------------+---------------------+--------------------+

如何在MySQL中获得那些225、237或209代码？哪个功能？哪个字符集？