安装mysql8

1.解压mysql

cd /usr/local

xz -d mysql-8.0.18-linux-glibc2.12-x86_64.tar.xz
tar -xvf mysql-8.0.18-linux-glibc2.12-x86_64.tar

2. 重命名安装包

mv mysql-8.0.18-linux-glibc2.12-x86_64 mysql

3. 创建用户和用户组

groupadd mysql
useradd -r -g mysql mysql

4. 修改mysql目录的所有用户和用户组

chown -R mysql:mysql mysql

5. 在mysql目录下创建文件夹（data、logs）、并切换到mysql用户

cd /usr/local/mysql
su mysql

mkdir data
mkdir logs
touch logs/mysqld.log
exit

6. 初始化数据库

cd /usr/local/mysql/bin

./mysqld --defaults-file=/etc/my.cnf --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --user=mysql --initialize

7.添加自启动服务

cd /usr/local/mysql/support-files/

cp mysql.server /etc/init.d/mysql

8.修改文件（/etc/init.d/mysql）中的两个变更值

vim /etc/init.d/mysql

basedir=/usr/local/mysql
datadir=/usr/local/mysql/data

9.修改my.cnf配置文件

cd /usr/local/mysql/bin

vim /etc/my.cnf

[client]
port=3306
socket=/tmp/mysql.sock

default-character-set=utf8mb4

[mysqld]
port=3306
socket=/tmp/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0

# skip #
skip-name-resolve=1
skip-external-locking=1

# general #
user=mysql
default-authentication-plugin=mysql_native_password
default-storage-engine=InnoDB
character-set-server=utf8mb4
collation-server=utf8mb4_unicode_ci

[mysqld_safe]
log-error=/usr/local/mysql/logs/mysqld.log

10.启动mysql服务

/etc/init.d/mysql start

11.修改mysql初始化root密码

./mysql -uroot -p

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