深入淺出MySQL(五) MySQL5.5的中文亂碼坑

這一次的記錄主要是針對mysql5.5版本里面的中文亂碼而言，這裏用到的操作系統是centos7，數據庫是mysql5.5，雲平臺是阿里雲

一、登錄MySQL查看用SHOW VARIABLES LIKE ‘character%’;下字符集，顯示如下：

+--------------------------+----------------------------+
| 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/ |
+--------------------------+----------------------------+

二、修改mysql的my.cnf文件中的字符集鍵值（注意配置的字段細節）：
1、在[client]字段里加入default-character-set=utf8，如下：

[client]
port = 3306
socket = /var/lib/mysql/mysql.sock
default-character-set=utf8

2、在[mysqld]字段里加入character-set-server=utf8，如下：

[mysqld]
port = 3306
socket = /var/lib/mysql/mysql.sock
character-set-server=utf8

3、在[mysql]字段里加入default-character-set=utf8，如下：

[mysql]
no-auto-rehash
default-character-set=utf8

修改完成後，使用命令：service mysql restart重啓mysql服務就生效。注意：[mysqld]字段與[mysql]字段是有區別的。
使用SHOW VARIABLES LIKE ‘character%’;查看，發現數據庫編碼全已改成utf8。

+--------------------------+----------------------------+
| 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/ |
+--------------------------+----------------------------+

‘

4、如果上面的都修改了還亂碼，那剩下問題就一定在connection連接層上。解決方法是在發送查詢前執行一下下面這句（直接寫在SQL文件的最前面）：
SET NAMES ‘utf8’;
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;