Centos7 安装 MySQL

• 1.查看是否有预装的 MYSQL 或者 MARIADB：

1. yum list installed|grep mysql
2. yum list installed |grep mariadb

• 2.卸载掉列出的包

1. yum y remove *

• 3.安装 MYSQL

1. 下载安装包
   wget http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm
2. 安装 MYSQL 源
   yum localinstall mysql57-community-release-el7-8.noarch.rpm

• 4.检查 MYSQL 是否安装成功

1. yum repolist enabled | grep "mysql.\*-community.\*"
2. yum install mysql-community-server

• 5.MYSQL5.7 安装后生成了初始 root 密码

1. 启动 MYSQL systemctl start mysqld
2. 查看初始密码
   grep 'temporary password' /var/log/mysqld.log

• 6.设置开机启动

1. systemctl enable mysqld
2. systemctl daemon-reload

• 7.配置文件

1. 密码规则太特殊，修改密码规则，如果不需要密码规则可以关闭

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

[mysqld]
#default encode utf-8
character_set_server=utf8
init_connect='SET NAMES utf8'
#
# 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
#password rules enable/disable
validate_password = off
#0(LOW) 1(MEDIUM) 2(STRONG)
validate_password_policy=0

• 8.END
  此时 MYSQL 配置基本完成，不过 ROOT 用户目前只能在本地登录，想要访问执行以下语句(先指定数据库 use *)
  grant all privileges on *.* to 'root'@'%'with grant option;