MySQL 編碼

1. 先設定 mysqld 服務的編碼
   

   [root@csie5 ~]# vim /etc/my.cnf 
   [mysqld]
   default-character-set=utf8
   default-collation=utf8_unicode_ci
   character-set-server=utf8
   collation-server=utf8_unicode_ci 
   
   datadir=/var/lib/mysql
   socket=/var/lib/mysql/mysql.sock
   user=mysql
   # Disabling symbolic-links is recommended to prevent assorted security risks
   symbolic-links=0
   
   [client]
   default-character-set=utf8
   
   [mysql]
   default-character-set=utf8
   
   [mysqld_safe]
   log-error=/var/log/mysqld.log
   pid-file=/var/run/mysqld/mysqld.pid
   

2. 重新啟動 mysqld 服務
   

   [root@csie5 ~]# /etc/init.d/mysqld restart
   

3. 登入 mysql 查詢 charset 變數，資料庫編碼為 character_set_database latin1。
   

   [root@csie5 ~]# mysql -uroot -p
   Enter password: 
   
   mysql> use ijait;
   mysql> show variables like 'character_set%';
   +--------------------------+----------------------------+
   | 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     | utf8                       |
   | character_set_system     | utf8                       |
   | character_sets_dir       | /usr/share/mysql/charsets/ |
   +--------------------------+----------------------------+
   8 rows in set (0.00 sec)
   

4. 使用 status; 或 \s 查詢也可以
   

   mysql> status;
   --------------
   mysql  Ver 14.14 Distrib 5.1.69, for redhat-linux-gnu (x86_64) using readline 5.1
   
   Connection id:		43
   Current database:	
   Current user:		root@localhost
   SSL:			Not in use
   Current pager:		stdout
   Using outfile:		''
   Using delimiter:	;
   Server version:		5.1.69 Source distribution
   Protocol version:	10
   Connection:		Localhost via UNIX socket
   Server characterset:	utf8
   Db     characterset:	latin1
   Client characterset:	utf8
   Conn.  characterset:	utf8
   UNIX socket:		/var/lib/mysql/mysql.sock
   Uptime:			59 min 12 sec
   
   Threads: 1  Questions: 1112  Slow queries: 0  Opens: 645  Flush tables: 1  Open tables: 64  Queries per second avg: 0.313
   --------------
   

5. 設定資料庫預設編碼為 utf8
   

   mysql> ALTER DATABASE ijait CHARACTER SET utf8 COLLATE utf8_general_ci;
   

6. 使用 status; 或 \s 再查詢，資料庫編碼已改 utf8。
   

   mysql> status;
   --------------
   mysql  Ver 14.14 Distrib 5.1.69, for redhat-linux-gnu (x86_64) using readline 5.1
   
   Connection id:		43
   Current database:	
   Current user:		root@localhost
   SSL:			Not in use
   Current pager:		stdout
   Using outfile:		''
   Using delimiter:	;
   Server version:		5.1.69 Source distribution
   Protocol version:	10
   Connection:		Localhost via UNIX socket
   Server characterset:	utf8
   Db     characterset:	utf8
   Client characterset:	utf8
   Conn.  characterset:	utf8
   UNIX socket:		/var/lib/mysql/mysql.sock
   Uptime:			59 min 12 sec
   
   Threads: 1  Questions: 1112  Slow queries: 0  Opens: 645  Flush tables: 1  Open tables: 64  Queries per second avg: 0.313
   --------------
   

7. 雖然資料庫編碼已改為 utf8，但其中的資料表還是原先的 latin1 編碼，為一次轉碼，先以預設編碼 latin1 匯出資料庫，資料庫中的中文字串會以系統預設的 utf8 編碼呈現。
   

   [root@csie5 ~]# cd /var/lib/mysql/
   [root@csie5 mysql]# mysqldump --user=root --password=rootpw --default-character-set=latin1 --skip-set-charset ijait > ijait.sql
   

8. 將資料庫中的 latin1 字串改成 utf8。
   

   [root@csie5 mysql]# sed -r 's/latin1/utf8/g' ijait.sql > ijait_utf.sql
   

9. 再將 utf8 編碼的資料庫重新匯入。
   

   [root@csie5 mysql]# mysql --user=root --password=rootpw --default-character-set=utf8 ijait < ijait_utf.sql
   

10. 資料庫雖已完全改成 utf8 編碼，OJS 網頁中中文顯示還是出現 '?????'，故必須設定 OJS。