通过MySQL命令行修改:

mysql> set character_set_client=utf8;
Query OK, 0 
rows affected (0.00 sec)

mysql> set character_set_connection=utf8;
Query OK, 
0 rows affected (0.00 sec)

mysql> set character_set_database=utf8;
Query OK, 0 
rows affected (0.00 sec)

mysql> set character_set_results=utf8;
Query OK, 0 
rows affected (0.00 sec)

mysql> set character_set_server=utf8;
Query OK, 0 
rows affected (0.00 sec)

mysql> set character_set_system=utf8;
Query OK, 0 
rows affected (0.01 sec)

mysql> set collation_connection=utf8;
Query OK, 0 
rows affected (0.01 sec)

mysql> set collation_database=utf8;
Query OK, 0 
rows affected (0.01 sec)

mysql> set collation_server=utf8;
Query OK, 0 rows 
affected (0.01 sec)

查看:
mysql> show variables like 
'character_set_%';
+--------------------------+----------------------------+
| 
Variable_name | Value 
|
+--------------------------+----------------------------+
| 
character_set_client | utf8 |
| character_set_connection | utf8 |
| 
character_set_database | utf8 |
| character_set_filesystem | binary |
| 
character_set_results | utf8 |
| character_set_server | utf8 |
| 
character_set_system | utf8 |
| character_sets_dir | 
/usr/share/mysql/charsets/ 
|
+--------------------------+----------------------------+
8 rows in set 
(0.03 sec)

mysql> show variables like 
'collation_%';
+----------------------+-----------------+
| Variable_name 
| Value |
+----------------------+-----------------+
| 
collation_connection | utf8_general_ci |
| collation_database | 
utf8_general_ci |
| collation_server | utf8_general_ci 
|
+----------------------+-----------------+
3 rows in set (0.04 sec)