centos 7.3 服务器环境搭建——MySQL 安装和配置
服务器信息如下:
服务器：阿里云
系统 centos 7.3 （阿里云该版本最新系统）
mysql版本：5.7.18 （当前时间最新版本）
连接服务器工具：xshell
1、 配置yum源
更新yum源
yum update
下载mysql源安装包
wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm
安装mysql源
yum localinstall mysql57-community-release-el7-8.noarch.rpm
检查mysql源是否安装成功
yum repolist enabled | grep "mysql.*-community.*"
安装MySQL
yum install mysql-community-server
注意：在这过程中会询问的都按y然后回车允许

2、安装MySQL
yum install mysql-community-server
3、启动MySQL
启动MySQL服务
systemctl start mysqld
查看MySQL的启动状态
systemctl status mysqld
设置MySQL开机启动
systemctl enable mysqld
systemctl daemon-reload
4、修改root默认密码
找到root默认密码
grep 'temporary password' /var/log/mysqld.log
进入mysql控制台, 输入上述查询到的默认密码
mysql -uroot -p
第一次登录必须修改初始密码：（最新mysql要求密码必须包含大小写字母和字符，长度大于等于8个字符）
alter user root@localhost identified by '连接密码!';
显示数据库内容
show databases;
查看端口号
show global variables like 'port';
5、添加远程登录用户
默认只允许root帐户在本地登录，如果要在其它机器上连接mysql，必须修改root允许远程连接，或者添加一个允许远程连接的帐户

添加远程帐户（密码同上规则）
GRANT ALL PRIVILEGES ON *.* TO 'test'@'%' IDENTIFIED BY '连接密码!' WITH GRANT OPTION;
立即生效
flush privileges;
退出mysql操作
exit

总结：
my.cnf文件：

# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.7/en/server-configuration-defaults.html

[mysqld]

#skip_grant_tables跳过密码直接登录

#validate_password=off 跳过密码强度验证（大小写+特殊字符+数字）
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M
#
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
#
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0

log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

#--------------------------

#将数据库切换至mysql库
mysql> USE mysql;
#修改密码
mysql> UPDATE user SET authentication_string=PASSWORD(‘数据库连接密码’)WHERE user=’root’;
#刷新MySQL权限相关的表
mysql> flush privileges;
mysql> exit;
添加远程账户访问：
grant all privileges on *.* to 'root'@'%%' identified by '数据库连接密码' with grant option;
立即生效：flush privileges;

update mysql.user set authentication_string=password('数据库连接密码') where user='root';

关闭密码验证：my.cnf文件中加入：validate_password=off
修改密码：
update user set authentication_string=password("数据库连接密码") where user='root';