MySQLの文字コードをUTF8に変更する手順

＠Fedora8、MySQL5.0.45。どの設定が実際何に使われているのか、詳しくは調べてないけど、全部UTF8にしておけば問題ないだろうという適当な推測に基づいて変更しておく手順をメモ。文字化けには悩みたくない。

mysql> show variables like "char%";
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | latin1                     | 
| character_set_connection | latin1                     | 
| character_set_database   | latin1                     | 
| character_set_filesystem | binary                     | 
| character_set_results    | latin1                     | 
| character_set_server     | latin1                     | 
| character_set_system     | utf8                       | 
| character_sets_dir       | /usr/share/mysql/charsets/ | 
+--------------------------+----------------------------+
8 rows in set (0.00 sec)

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

mysql> show variables like "char%";
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       | 
| character_set_connection | utf8                       | 
| character_set_database   | latin1                     | 
| character_set_filesystem | binary                     | 
| character_set_results    | utf8                       | 
| character_set_server     | latin1                     | 
| character_set_system     | utf8                       | 
| character_sets_dir       | /usr/share/mysql/charsets/ | 
+--------------------------+----------------------------+
8 rows in set (0.00 sec)

設定ファイルに↓を追記して再起動かけます。

# cd /etc/
# vi my.cnf

[mysqld]
default-character-set=utf8
# /etc/init.d/mysqld restart
MySQL を停止中:                                            [  OK  ]
MySQL を起動中:                                            [  OK  ]

mysql> show variables like "char%";
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | latin1                     | 
| character_set_connection | latin1                     | 
| character_set_database   | utf8                       | 
| character_set_filesystem | binary                     | 
| character_set_results    | latin1                     | 
| character_set_server     | utf8                       | 
| character_set_system     | utf8                       | 
| character_sets_dir       | /usr/share/mysql/charsets/ | 
+--------------------------+----------------------------+
8 rows in set (0.00 sec)

mysql> show variables like "char%";
+--------------------------+----------------------------+
| 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 (0.00 sec)

既に作成済みのDBの文字コードを変更する場合は
ALTER DATABASE　〜
ALTER TABLE　〜
ALTER TABLE ALTER COLUMN　〜
などでDEFAULT CHARACTER SETを変更。