为什么选择MySQL数据库？
毫无疑问，绝大多数的使用linux操作系统的大中小型互联网网站都在使用MySQL作为其后端的数据库存储，从大型的BAT门户，到电商平台，分类门户等无一例都使用MySQL数据库。
My Sql 数据库优点：
1、性能卓越，服务稳定，很少出现异常宕机
2、开放源代码且无版权约束，自主性及使用成本低
3、历史悠久，社区及用户非常活跃，遇到问题，可以寻求帮助
4、软件体积小，安排使用简单，并且易于维护，安装及维护成本低
5、品牌口碑效应，使得企业无需考虑直接用之，LAMP,LEMP流行架构
6、支持多操作系统，提供多种API接口，支持多种开发语言，特别对流行的PHP语言有很好支持
linux软件的安装方式：
1、 yum/rpm：简单 快，无法定制。
2、 编译安装：比较复杂，速度慢，可定制。
./configure;make;make install gmake;gmake insall
3、 二进制包*****
直接解压就能用（类似于绿色软件，无需安装） 简单，快，不好定制。
下面我们选择二进制包方法：
1、创建mysql用户
[root@lamp01 tools]# id mysql
id: mysql：无此用户
[root@lamp01 tools]# groupadd mysql
[root@lamp01 tools]# useradd -s /sbin/nologin -g mysql -M mysql
[root@lamp01 tools]# id mysql
uid=503(mysql) gid=503(mysql) 组=503(mysql)
[root@lamp01 tools]#
2、下载或上传mysql二进制软件包并解压
[root@lamp01 tools]# tar xf ./mysql-5.5.32-linux2.6-x86_64.tar.gz
[root@lamp01 tools]# ll
总用量 182352
drwxr-xr-x. 13 root root 4096 1月 10 21:54 mysql-5.5.32-linux2.6-x86_64
-rw-r--r--. 1 root root 186722932 1月 10 21:51 mysql-5.5.32-linux2.6-x86_64.tar.gz
3、将解压的文件移动到安装目录下，并做软连接（隐藏版本号安全）
[root@lamp01 tools]# mv mysql-5.5.32-linux2.6-x86_64 /application/mysql-5.5.32
[root@lamp01 tools]# ln -s /application/mysql-5.5.32/ /application/mysql
[root@lamp01 tools]# ll /application/总用量 8l
rwxrwxrwx. 1 root root 26 1月 10 21:57 mysql -> /application/mysql-5.5.32/
drwxr-xr-x. 13 root root 4096 1月 10 21:54 mysql-5.5.32
lrwxrwxrwx. 1 root root 25 12月 19 03:30 nginx -> /application/nginx-1.6.3/
drwxr-xr-x. 11 root root 4096 12月 20 21:12 nginx-1.6.3
[root@lamp01 tools]#
操作到此步骤相当于编译安装make install 之后。
4、初始化数据库
[root@lamp01 tools]# /application/mysql/scripts/mysql_install_db --basedir=/application/mysql/ --datadir=/application/mysql/data/ --user=mysql
Installing MySQL system tables...
OK
Filling help tables...
OK
解释：
/application/mysql/scripts/mysql_install_db //指定安装的命令
--basedir //指定mysql安装的目录
--datadir //存放数据文件的目录
--user //mysql用户
5、授权mysql管理数据库文件
[root@lamp01 tools]# chown -R mysql.mysql /application/mysql/
[root@lamp01 tools]# cd /application/mysql/
[root@lamp01 mysql]# ll support-files/*.cnf
-rw-r--r--. 1 mysql mysql 4691 6月 19 2013 support-files/my-huge.cnf
-rw-r--r--. 1 mysql mysql 19759 6月 19 2013 support-files/my-innodb-heavy-4G.cnf
-rw-r--r--. 1 mysql mysql 4665 6月 19 2013 support-files/my-large.cnf
-rw-r--r--. 1 mysql mysql 4676 6月 19 2013 support-files/my-medium.cnf
-rw-r--r--. 1 mysql mysql 2840 6月 19 2013 support-files/my-small.cnf
[root@lamp01 mysql]#
6、生成mysql配置文件
\cp /application/mysql/support-files/my-small.cnf /etc/my.cnf
7、配置启动mysql
[root@lamp01 mysql]# sed -i 's#/usr/local/mysql#/application/mysql#g' /application/mysql/bin/mysqld_safe /application/mysql/support-files/mysql.server
[root@lamp01 mysql]# cp /application/mysql/support-files/mysql.server /etc/init.d/mysqld #将生成的启动脚本拷贝到init.d目录下
[root@lamp01 mysql]# chmod +x /etc/init.d/mysqld #授予可执行权限
[root@lamp01 mysql]# lsof -i:3306 #查询mysql服务是否开启
[root@lamp01 mysql]# /etc/init.d/mysqld start
Starting MySQL.. SUCCESS!
[root@lamp01 mysql]#
8、配置环境变量
vi /etc/profile
PATH="/application/mysql/bin:$PATH"
source /etc/profile
也可以把mysql命令放到已经有环境变量的路径里
[root@lamp01 mysql]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin
[root@lamp01 mysql]# cp /application/mysql/bin/* /usr/local/sbin/
[root@lamp01 mysql]# which mysql
/usr/local/sbin/mysql
[root@lamp01 mysql]#
9、登陆测试
[root@lamp01 mysql]# mysql
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.32 MySQL Community Server (GPL)
Copyright (c) 2000, 2013, 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>
出现以上提示符表示mysql已经安装ok了。如果安装时或者工作中有问题，可以看错误日志分析问题原因：
cat /application/mysql/data/mysql-server.err
10、设置及更改mysql密码
[root@lamp01 mysql]# mysqladmin -uroot password "123456"
[root@lamp01 mysql]# mysql
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
[root@lamp01 mysql]# mysql -uroot -p123456
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.5.32 MySQL Community Server (GPL)
Copyright (c) 2000, 2013, 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>
更改密码：
[root@lamp01 mysql]# mysqladmin -uroot -p123456 password "bqh123"
[root@lamp01 mysql]# mysql -uroot -p123456
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
[root@lamp01 mysql]# mysql -uroot -pbqh123
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 7
Server version: 5.5.32 MySQL Community Server (GPL)
Copyright (c) 2000, 2013, 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>
为了安全起见，我们在登陆时，采用交互式登陆
[root@lamp01 mysql]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 5.5.32 MySQL Community Server (GPL)
Copyright (c) 2000, 2013, 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>
11、安全优化：删除不必要的库和用户
删除test库：dro database test;
删除无用用户（保留root和localhost）
drop user '用户'@‘主机’;
注意：主机大写或者特殊字符删不了，需用
delete from mysql.user where user='用户' and host='主机大写或特殊字符';
如果不小心把这两个也给删除了，恢复方法：
grant all on *.* to ‘root’@localhostt identified by ‘密码’ with grant option;
flush privileges; #刷新权限
mysql简单的命令：
查看所有库：show databases;
切库：use mysql;
查看用户列表：select user,host from mysql.user
查看当前用户：select user();
查看当前所在库：select database();
删除数据库：drop database 库名；
删除用户：drop user '用户'@'主机';