latin1のDBからdumpしたデータをutf8のDBに移行するよー

• 移行元 DB:hoge

mysql> show variables like 'collation%';
+----------------------+-------------------+
| Variable_name        | Value             |
+----------------------+-------------------+
| collation_connection | latin1_swedish_ci | 
| collation_database   | latin1_swedish_ci | 
| collation_server     | latin1_swedish_ci | 
+----------------------+-------------------+
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/mysql/charsets/       | 
+--------------------------+----------------------------+

残念ながらdefaultがlatin1ですが、DB自体はutf8で作っているのでuse hogeした後見ると

mysql> show variables like 'collation%';
+----------------------+-------------------+
| Variable_name        | Value             |
+----------------------+-------------------+
| collation_connection | latin1_swedish_ci | 
| collation_database   | utf8_general_ci   | 
| collation_server     | latin1_swedish_ci | 
+----------------------+-------------------+
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     | latin1                     | 
| character_set_system     | utf8                       | 
| character_sets_dir       | /usr/share/mysql/charsets/ | 
+--------------------------+----------------------------+

となっています。

• 以降先 DB:hoge

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 (0.00 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/ | 
+--------------------------+----------------------------+

根っからのUTF8仕様。

というわけでまずdefault charsetをlatin1に指定してdump

mysqldump -u username -p hoge --default-character-set=latin1 > backup.sql

dumpしたデータをlatin1対応のエディタ（サクラエディタにしました）で開いて、SET NAMES追加

-- MySQL dump 10.11
--
-- Host: localhost    Database: hoge
-- ------------------------------------------------------
# ↑このメッセージがあるあたりに追加
SET NAMES utf8;

保存して、リストア

mysql -u username -p hoge < backup.sql

元々latin1の設定になってるmysqlにutf8のDBを作るとdumpでcharset指定してやらないとうまくいかないんですね。
無事に移行できました。