MySQL下载地址：http://dev.mysql.com/downloads/mysql/
1、Windows下安装MySQL
我下的是最新版的MySQL，解压后，目录如下：
将解压目录下默认文件 my-default.ini 拷贝一份，改名 my.ini
复制下面的配置信息到 my.ini 保存
#如果没有my-default.ini,可自己新建my.ini或者从其他地方中获取
#########################################################
[client]
port=3306
default-character-set=utf8
[mysqld]
port=3306
character_set_server=utf8
#character_set_server=utf8 一定要这样写;
basedir=D:Program FilesMySQLmysql-5.6.16-win32
#解压目录
datadir=D:Program FilesMySQLmysql-5.6.16-win32data
#解压目录下data目录,必须为data目录
sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES
#########################################################
添加环境变量
操作如下：
在path环境变量下加入：D:Program FilesMySQLmysql-5.6.16-win32in
可以看到上图，MySQL5.7它没有data目录，如果没有data目录，安装后启动的时候就会报这个错：
D:Servicemysql57in>net start mysql
MySQL 服务正在启动 .
MySQL 服务无法启动。
服务没有报告任何错误。
请键入 NET HELPMSG 3534 以获得更多的帮助。
为了避免这个错误，需要使用命令生成data文件夹，按如下步骤安装
1. 进入dos的命令行，一定要用administrator进入。
2. 进入MySQL的bin目录，输入mysqld –install可以安装MySQL
D:>cd D:Servicemysql57in
D:Servicemysql57in>mysqld -install
Service successfully installed.
3. 输入以下命令，可以初始化MySQL数据库，初始化了之后，会打印出MySQL的默认生成的密码，下面标红了的就是默认生成的密码。
D:Servicemysql57in>mysqld --initialize --user=root --console
2015-12-20T08:13:45.264865Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2015-12-20T08:13:45.854579Z 0 [Warning] InnoDB: New log files created, LSN=45790
2015-12-20T08:13:45.998772Z 0 [Warning] InnoDB: Creating foreign key constraint system tables.
2015-12-20T08:13:46.098118Z 0 [Warning] No existing UUID has been found, so we assume that this is the first time that this server has been started. Generating a new UUID: 9755c3ea-a6f1-11e5-81a3-74d02b122fb3.
2015-12-20T08:13:46.121617Z 0 [Warning] Gtid table is not ready to be used. Table 'mysql.gtid_executed' cannot be opened.
2015-12-20T08:13:46.135153Z 1 [Note] A temporary password is generated for root@localhost: g!gRw!d%M0Sj
初始化了以后，可以看到MySQL目录下，多了data目录
4. 启动MySQL服务
D:Servicemysql57in>net start mysql
MySQL 服务正在启动 .
MySQL 服务已经启动成功。
5. 使用默认生成的密码，进入mysql
D:Servicemysql57in>mysql -u root -p
Enter password: ************
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 4
Server version: 5.7.10
Copyright (c) 2000, 2015, 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>
6. 进入了mysql就可以修改默认密码了（我把默认密码修改成了root）
mysql> set password = password('root') ;
这个时候，Windows下的MySQL环境就已经安装好了。
2、Linux下安装MySQL如果有网络的话，Linux下安装就简单多了，我这用的CentOS安装的
1. 安装MySQL服务，下面用yum安装，它会自动安装需要的依赖包，很方便，但是要用root用户来安装
[root@bogon ~]# yum install mysql-server
2. 启动MySQL服务，第一次启动服务会有点慢
[root@bogon ~]# /etc/init.d/mysqld restart
3. 启动了MySQL服务，就可以使用ps命令，可以查看到MySQL这个服务，说明服务已经启动了
[root@bogon ~]# ps -ef | grep mysql
root 3474 1 0 22:29 pts/0 00:00:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --socket=/var/lib/mysql/mysql.sock --pid-file=/var/run/mysqld/mysqld.pid --basedir=/usr --user=mysql
mysql 3576 3474 0 22:29 pts/0 00:00:00 /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --user=mysql --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock
root 3614 3334 0 22:34 pts/0 00:00:00 grep mysql
4. 直接输入mysql就可以进入MySQL了
[root@bogon ~]# mysql
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 3
Server version: 5.1.73 Source distribution
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>
5. 设置MySQL的密码，我这边设置密码为root，以后就可以用这个密码来登录MySQL了
mysql> set password = password('root');
Query OK, 0 rows affected (0.00 sec)