1、找到my.cnf配置文件
如果/etc/目錄下沒有my.cnf配置文件，請到/usr/share/mysql/下找到*.cnf文件，拷貝其中一個到/etc/並改名為my.cnf)中。命令如下：
[root@test1 mysql]# cp /usr/share/mysql/my-medium.cnf /etc/my.cnf
mysql5.5.10默認字符集修改，字元編碼設置，中文亂碼，gb2312，gbk，utf8格式存儲數據
通過修改mysql默認字符集，可以存儲中文數據，以免出現中文亂碼，以下以設置為utf8為例。
=================================================================================
以下內容是在本機安裝的mysql-5.5.10上,沒有修改my.ini前顯示結果
===================================================================================
mysql> show variables like 'character%';
+--------------------------+---------------------------------+
| Variable_name | Value |
+--------------------------+---------------------------------+
| character_set_client | gbk |
| character_set_connection | gbk |
| character_set_database | latin1 |
| character_set_filesystem | binary |
| character_set_results | gbk |
| character_set_server | latin1 |
| character_set_system | utf8 |
| character_sets_dir |/usr/share/mysql/charsets/ |
+--------------------------+---------------------------------+
8 rows in set (0.02 sec)
mysql> show variables like 'collation%';
+----------------------+-------------------+
| Variable_name | Value |
+----------------------+-------------------+
| collation_connection | gbk_chinese_ci |
| collation_database | latin1_swedish_ci |
| collation_server | latin1_swedish_ci |
+----------------------+-------------------+
3 rows in set (0.00 sec)
==============================================================================
關閉mysql服務，在mysql安裝目錄下，my.ini文件進行如下修改，沒有則直接進行添加
==============================================================================
[client]
#修改客戶端默認字元編碼格式為utf8
default-character-set=utf8
[mysqld]
#修改伺服器端默認字元編碼格式為utf8
character-set-server = utf8
=============================================================================
修改後，再次輸入命令查看，顯示結果如下
==============================================================================
mysql> show variables like 'character%';
+--------------------------+---------------------------------+
| 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)
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)
================================================================================
查看mysql已經安裝的所有字符集，也就是在mysql中可以使用的字符集，結果如下
================================================================================
mysql> show character set;
+----------+-----------------------------+---------------------+--------+
| Charset | Description | Default collation | Maxlen |
+----------+-----------------------------+---------------------+--------+
| big5 | Big5 Traditional Chinese | big5_chinese_ci | 2 |
| dec8 | DEC West European | dec8_swedish_ci | 1 |
| cp850 | DOS West European | cp850_general_ci | 1 |
| hp8 | HP West European | hp8_english_ci | 1 |
| koi8r | KOI8-R Relcom Russian | koi8r_general_ci | 1 |
| latin1 | cp1252 West European | latin1_swedish_ci | 1 |
| latin2 | ISO 8859-2 Central European | latin2_general_ci | 1 |
| swe7 | 7bit Swedish | swe7_swedish_ci | 1 |
| ascii | US ASCII | ascii_general_ci | 1 |
| ujis | EUC-JP Japanese | ujis_japanese_ci | 3 |
| sjis | Shift-JIS Japanese | sjis_japanese_ci | 2 |
| hebrew | ISO 8859-8 Hebrew | hebrew_general_ci | 1 |
| tis620 | TIS620 Thai | tis620_thai_ci | 1 |
| euckr | EUC-KR Korean | euckr_korean_ci | 2 |
| koi8u | KOI8-U Ukrainian | koi8u_general_ci | 1 |
| gb2312 | GB2312 Simplified Chinese | gb2312_chinese_ci | 2 |
| greek | ISO 8859-7 Greek | greek_general_ci | 1 |
| cp1250 | Windows Central European | cp1250_general_ci | 1 |
| gbk | GBK Simplified Chinese | gbk_chinese_ci | 2 |
| latin5 | ISO 8859-9 Turkish | latin5_turkish_ci | 1 |
| armscii8 | ARMSCII-8 Armenian | armscii8_general_ci | 1 |
| utf8 | UTF-8 Unicode | utf8_general_ci | 3 |
| ucs2 | UCS-2 Unicode | ucs2_general_ci | 2 |
| cp866 | DOS Russian | cp866_general_ci | 1 |
| keybcs2 | DOS Kamenicky Czech-Slovak | keybcs2_general_ci | 1 |
| macce | Mac Central European | macce_general_ci | 1 |
| macroman | Mac West European | macroman_general_ci | 1 |
| cp852 | DOS Central European | cp852_general_ci | 1 |
| latin7 | ISO 8859-13 Baltic | latin7_general_ci | 1 |
| utf8mb4 | UTF-8 Unicode | utf8mb4_general_ci | 4 |
| cp1251 | Windows Cyrillic | cp1251_general_ci | 1 |
| utf16 | UTF-16 Unicode | utf16_general_ci | 4 |
| cp1256 | Windows Arabic | cp1256_general_ci | 1 |
| cp1257 | Windows Baltic | cp1257_general_ci | 1 |
| utf32 | UTF-32 Unicode | utf32_general_ci | 4 |
| binary | Binary pseudo charset | binary | 1 |
| geostd8 | GEOSTD8 Georgian | geostd8_general_ci | 1 |
| cp932 | SJIS for Windows Japanese | cp932_japanese_ci | 2 |
| eucjpms | UJIS for Windows Japanese | eucjpms_japanese_ci | 3 |
+----------+-----------------------------+---------------------+--------+
39 rows in set (0.00 sec)
===============================================================================
經過所有以上設置以後，mysql中所有字符集都是utf8的了，但是在控制台操作的時候，還是會出現亂碼中文亂碼。
這是因為windows XP的控制台窗口默認顯示字元編碼格式為gbk，所以這裡要設置顯示結果使用的字元編碼格式為utf8。
每次在控制台進行操作的時候，都要進行如下這個設置，結果才能正常顯示中文
===============================================================================
mysql> set character_set_results='gbk';
Query OK, 0 rows affected (0.00 sec)
===============================================================================
一般就算設置了表的默認字符集為utf8並且通過UTF-8編碼發送查詢，你會發現存入資料庫的仍然是亂碼。
問題就出在這個connection連接層上。解決方法是在發送查詢前執行一下下面這句：
===============================================================================
mysql> set names gbk;
Query OK, 0 rows affected (0.00 sec)
它相當於下面的三句指令：
SET character_set_client = utf8;
SET character_set_results = utf8;
SET character_set_connection = utf8;
因此，這個方法也可以解決所有字元編碼設置為utf8，而控制台顯示中文亂碼的問題。