如果为该列设置了适当的排序规则，则该字段中的值自然会与其相等的未重音进行比较.

If you set an appropriate collation for the column then the value within the field will compare equal to its unaccented equivalent naturally.

mysql> SET NAMES 'utf8' COLLATE 'utf8_unicode_ci';
Query OK, 0 rows affected (0.00 sec)

mysql> SELECT 'é' = 'e';
+------------+
| 'é' = 'e' |
+------------+
|          1 |
+------------+
1 row in set (0.05 sec)