linux 下 mysql安装和配置

最近在学习R语言，看到R与数据库交互这一部分，就自己动手实践了一下，数据库选择的是mysql，主要记录下linux下怎么安装mysql。

网上的很多资料都有相关的文章，这里只是记录下自己安装过程中遇到的问题和解决方法：

linux内核版本：

~$ uname -a
Linux naci 3.19.0-16-generic #16-Ubuntu SMP Thu Apr 30 16:09:58 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

---

1.首先在liunx下安装Mysql数据库

~$ sudo apt-get install mysql-server  #安装Mysql服务器端
~$ ps -aux|grep mysql                 #检查Mysql服务器进程
beili    10301  0.0  0.0  37080  3604 pts/7    S+    5月20   0:00 mysql -u root -p
mysql    25125  0.0  0.0   4472  1704 ?        Ss   09:51   0:00 /bin/sh /usr/bin/mysqld_safe
mysql    25496  0.0  3.1 859956 127084 ?       Sl   09:51   0:01 /usr/sbin/mysqd --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib/mysql/plugin --log-error=/var/log/mysql/error.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/run/mysqld/mysqld.sock --port=3306
beili    26652  0.0  0.0  13708  2180 pts/19   S+   10:32   0:00 grep --color=auto mysql

~$ netstat -nlt|grep 3306             #检查Mysql服务器占用端口
tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN   

~$ /etc/init.d/mysql status           # 通过启动命令检查Mysql服务器状态
   Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
   Active: active (running) since 四 2015-05-21 09:51:13 CST; 43min ago
  Process: 25126 ExecStartPost=/usr/share/mysql/mysql-systemd-start post (code=exited, status=0/SUCCESS)
  Process: 25122 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)

~$ service mysql status               # 通过系统服务检查Mysql服务器状态
● mysql.service - MySQL Community Server
   Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
   Active: active (running) since 四 2015-05-21 09:51:13 CST; 44min ago
  Process: 25126 ExecStartPost=/usr/share/mysql/mysql-systemd-start post (code=exited, status=0/SUCCESS)
  Process: 25122 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
~$ whereis mysql                      # 查看mysql各个文件安装的目录
mysql: /usr/bin/mysql /usr/lib/mysql /etc/mysql /usr/include/mysql /usr/share/mysql /usr/share/man/man1/mysql.1.gz

---

2.访问和配置Mysql

$ mysql -u root -p
Enter password: 

mysql默认的字符集为latin1的，所以要改为utf8的。很多网上的文章执行“sudo vi /etc/mysql/my.cnf”，可是打开一看，里面就两行话：

!includedir /etc/mysql/conf.d/
!includedir /etc/mysql/mysql.conf.d/

想来mysql的配置文件应该是在那两个文件夹下面，于是尝试之下打开了/etc/mysql/mysql.conf.d/ 下的mysqld.cnf文件，执行下面的命令：

~$ sudo vi /etc/mysql/mysql.conf.d/mysqld.cnf
...
[client]
default-character-set=utf8

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

[mysqld]
character-set-server=utf8
collation-server=utf8_general_ci
...

注：棕色部分是添加的内容

重启mysql服务，并查看字符集的设置情况：

~$ sudo /etc/init.d/mysql restart
~$ mysql -u root -p
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/ |
+--------------------------+----------------------------+