Ubuntu修改mysql預設編碼

修改mysql的設定檔,使資料庫與伺服器作業系統的字元集設定一致。
    vi /etc/my.cnf 設定(如果沒有發現這個檔案，就建立1個)
    [mysqld]
    datadir=/var/lib/mysql
    socket=/var/lib/mysql/mysql.sock
    default-character-set=utf8  (增加的關鍵一句,使得資料庫預設以utf8儲存)
    當然，修改後，要重啟資料庫。
   
    再次用mysql -u root -p命令進入資料庫系統，用SHOW VARIABLES LIKE 'character_set_%';命令查看到如下內容：
+--------------------------+-----------------------------------------------------------------------+
| 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/local/mysql-5.1.20-beta-linux-i686-glibc23/share/mysql/charsets/ |
+--------------------------+-----------------------------------------------------------------------+
    發現關鍵項目已經用了utf8，但這樣還不夠，還要保證用戶端也是用utf8的字元集來操作的。
    登入的時候，要用以下命令：mysql --default-character-set=utf8 -u root -p
  
    再次用SHOW VARIABLES LIKE 'character_set_%';命令查看，結果變成了：
+--------------------------+-----------------------------------------------------------------------+
| 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/local/mysql-5.1.20-beta-linux-i686-glibc23/share/mysql/charsets/ |
+--------------------------+-----------------------------------------------------------------------+
    這樣才能保證用戶端所發命令都是基於utf8格式的，比如說建立資料庫和表，預設就會以utf8編碼，而無須再次指定。

需要說明一下，如果在修改編碼之前已經建好資料庫，需要刪掉原來，重建立立資料庫。