Ubuntu 12.04,安裝了MySQL，完了之後，更改了字符編譯，就報錯。感覺很郁悶。
環境：
root@ubuntu:~# uname -a
Linux ubuntu 3.2.0-23-generic #36-Ubuntu SMP Tue Apr 10 20:39:51 UTC 2012 x86_64 x86_64 x86_64 GNU/Linux
使用的 apt-get install mysql-server安裝的，然後改變了一下默認的字符集，在/etc/mysql/my.cnf裡面的[mysqld]和[client]裡加了
default-character-set=utf8，重啟就不行了。
root@ubuntu:~# service mysql start
start: Job failed to start
看了系統日志，報了以下內容
Jun 11 22:56:42 ubuntu kernel: [ 4051.584941] init: mysql main process (4021) terminated with status 7
Jun 11 22:56:42 ubuntu kernel: [ 4051.584981] init: mysql main process ended, respawning
Jun 11 22:56:43 ubuntu kernel: [ 4052.134766] init: mysql post-start process (4022) terminated with status 1
Jun 11 22:56:43 ubuntu kernel: [ 4052.154739] type=1400 audit(1339469803.511:40): apparmor="STATUS" operation="profile_replace" name="/usr/sbin/mysqld" pid=4068 comm="apparmor_parser"
Jun 11 22:56:44 ubuntu kernel: [ 4053.619246] init: mysql main process (4072) terminated with status 7
Jun 11 22:56:44 ubuntu kernel: [ 4053.619296] init: mysql main process ended, respawning
Jun 11 22:56:45 ubuntu kernel: [ 4054.248707] init: mysql post-start process (4073) terminated with status 1
Jun 11 22:56:45 ubuntu kernel: [ 4054.269778] type=1400 audit(1339469805.627:41): apparmor="STATUS" operation="profile_replace" name="/usr/sbin/mysqld" pid=4119 comm="apparmor_parser"
Jun 11 22:56:47 ubuntu kernel: [ 4055.733347] init: mysql main process (4123) terminated with status 7
Jun 11 22:56:47 ubuntu kernel: [ 4055.733389] init: mysql respawning too fast, stopped
root@ubuntu:~#
URL：http://www.bianceng.cn/OS/Linux/201410/46058.htm
糾結了很長時間，今天無意中測試，意外解決了問題，呵呵，不得不說，RP爆發。
配置文件如下
root@ubuntu:/etc/mysql# cat /etc/mysql/my.cnf | grep -v '^#'
[client]
default-character-set=utf8 #這裡其實不用指定的，如果要指定，要用這個指令。
port = 3306
socket = /var/run/mysqld/mysqld.sock
[mysqld_safe]
socket = /var/run/mysqld/mysqld.sock
nice = 0
[mysqld]
character_set_server=utf8 #要使用這個命令，default-character-set=utf8會報錯
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
lc-messages-dir = /usr/share/mysql
skip-external-locking
bind-address = 127.0.0.1
key_buffer = 16M
max_allowed_packet = 16M
thread_stack = 192K
thread_cache_size = 8
myisam-recover = BACKUP
query_cache_limit = 1M
query_cache_size = 16M
expire_logs_days = 10
max_binlog_size = 100M
[mysqldump]
quick
quote-names
max_allowed_packet = 16M
[mysql]
[isamchk]
key_buffer = 16M
!includedir /etc/mysql/conf.d/
root@ubuntu:/etc/mysql#
可以看出，在[client]和[myslqd]段中，設置字符編碼使用的指令不一樣。
然後重啟mysql就可以了
root@ubuntu:/etc/mysql# service mysql restart
mysql stop/waiting
mysql start/running, process 6981
root@ubuntu:/etc/mysql# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 147
Server version: 5.5.22-0ubuntu1 (Ubuntu)
Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> show variables like '%char%';
+--------------------------+----------------------------+
| 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)