CentOS 8.0安装MYSQL8.0.20

• 创建mysql文件夹

cd /use/loca
mkdir mysql
cd mysql

• 下载mysql8.0安装包

wget https://dev.mysql.com/get/Downloads/MySQL-8.0/mysql-8.0.20-linux-glibc2.12-x86_64.tar.xz

官网地址：https://dev.mysql.com/downloads/mysql/

• 解压mysql8.0安装包

tar xvJf mysql-8.0.20-linux-glibc2.12-x86_64.tar.xz 

• 重命名解压出来的文件夹，这里改成mysql-8.

mv mysql-8.0.20-linux-glibc2.12-x86_64 mysql-8.0

• /use/local/mysql文件夹下创建data文件夹 存储文件

mkdir data

• 分别创建用户组以及用户和密码（如果提示已存在说明之前有创建过了）

groupadd mysql
useradd -g mysql mysql

• 授权刚刚新建的用户

chown -R mysql.mysql /usr/local/mysql/mysql-8.0
chmod 750 /usr/local/mysql/data -R

• 配置环境，编辑/etc/profile文件

vim /etc/profile

在最后一行加
export PATH=$PATH:/usr/local/mysql/mysql-8.0/bin:/usr/local/mysql/mysql-8.0/lib

• 编辑my.cnf文件

vi /etc/my.cnf

按下面复制进去就好了，#号开头的不用管，一样，添加完之后，换行，打出“：sq”，用来保存文件并退出

[mysql]
default-character-set=utf8mb4
[client]
#port=3306
socket=/var/lib/mysql/mysql.sock

[mysqld]
#port=3306
#server-id=3306
user=mysql
general_log = 1
general_log_file= /var/log/mysql/mysql.log
socket=/var/lib/mysql/mysql.sock
basedir=/usr/local/mysql/mysql-8.0
datadir=/usr/local/mysql/data
log-bin=/usr/local/mysql/data/mysql-bin
innodb_data_home_dir=/usr/local/mysql/data
innodb_log_group_home_dir=/usr/local/mysql/data/
character-set-server=utf8mb4
lower_case_table_names=1
autocommit=1
default_authentication_plugin=mysql_native_password
symbolic-links=0
# Disabling symbolic-links is recommended to prevent assorted security risks
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd
#分组查询
sql_mode=NO_ENGINE_SUBSTITUTION
#最大执行字符穿
group_concat_max_len=102400
#连接数
max_connections=1000

[mysqld_safe]
log-error=/usr/local/mysql/data/mysql.log
pid-file=/usr/local/mysql/data/mysql.pid

#
# include all files from the config directory

• 切换到/usr/local/mysql/mysql-8.0/bin目录下

cd bin

• 初始化基础信息,得到数据库的初始密码（在/usr/local/mysql/mysql-8.0/bin目录下执行）

./mysqld --user=mysql --basedir=/usr/local/mysql/mysql-8.0 --datadir=/usr/local/mysql/data/ --initialize

注意此时要注意日志里面会打印出初始密码。最好保存到本地。

• 复制 mysql.server 文件，在/usr/local/mysql/mysql-8.0目录下执行

cp -a ./support-files/mysql.server /etc/init.d/mysql 
cp -a ./support-files/mysql.server /etc/init.d/mysqld

• 赋予权限

chown 777 /etc/my.cnf
chmod +x /etc/init.d/mysql
chmod +x /etc/init.d/mysqld

• 检查一下/var/lib/mysql是否存在，否则进行创建

mkdir /var/lib/mysql 

• 然后再赋予权限

chown -R mysql:mysql /var/lib/mysql/ 

• 启动数据库，有SUCCESS字眼说明MySQL安装完成

service mysql start

• 登录MySQL

mysql -u root -p

输入初始密码

• 修改数据库root账号的密码，并设置可以远程访问（因为root默认是不能远程访问的）

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '新密码';

• 执行flush privileges; 使密码生效

flush privileges;

• 选择数据库

 use mysql;

• 再修改远程连接并生效

update user set host='%' where user='root';

• 执行提交命令，搞定！

flush privileges;