我的操作如下：
sudo gedit /etc/mysql/my.cnf
其文件内容如下：

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

[mysqld_safe]
socket = /var/run/mysqld/mysqld.sock
nice = 0

[mysqld]
default-character-set=utf8


user = mysql
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
tmpdir = /tmp
language = /usr/share/mysql/english
skip-external-locking

key_buffer = 16M
max_allowed_packet = 16M
thread_stack = 128K
thread_cache_size = 8

query_cache_limit = 1M
query_cache_size = 16M


[mysqldump]
quick
quote-names
max_allowed_packet = 16M

[mysql]
#no-auto-rehash # faster start of mysql but no tab completition

[isamchk]
key_buffer = 16M

#
# * IMPORTANT: Additional settings that can override those from this file!
# The files must end with '.cnf', otherwise they'll be ignored.
#
!includedir /etc/mysql/conf.d/



但是最后insrt into 后还是出现了乱码。我也在连接数据库的文件下加了 mysql_query("set name gb2312");