【MySQL】8.0安装和配置

安装

• 安装yum源

wget http://repo.mysql.com/mysql80-community-release-el7-5.noarch.rpm

sudo yum -y install mysql80-community-release-el7-5.noarch.rpm

rpm --import https://repo.mysql.com/RPM-GPG-KEY-mysql-2022

• 查看mysql的yum源

cd /etc/yum.repos.d && ll

-rw-r--r-- 1 root root 1864 2月  22 2018 mysql-community.repo
-rw-r--r-- 1 root root 1885 2月  22 2018 mysql-community-source.repo

• 使用yum安装mysql服务

yum install mysql-community-server -y

• 检查是否已经设置为开机启动mysql服务

systemctl list-unit-files|grep mysqld

mysqld.service                                enabled 
mysqld@.service                               disabled

以上表示mysql已经设置为开机启动

• 设置mysql开机启动

systemctl enable mysqld.service

• 启动mysql服务

systemctl start mysqld.service

• 查看mysql服务状态

systemctl status mysqld.service

卸载

• 查看是否有安装mysql版本组件

rpm -qa|grep mysql

• 卸载MySQL服务

rpm -ev [需要移除组件的名称]

rpm -e --nodeps [需要移除组件的名称] 

此命令为强制卸载

• 删除数据库文件

sudo rm -rf /var/lib/mysql/*

配置

• 初始化mysql，并设置表名不区分大小写

mysqld --initialize --lower-case-table-names=1

如果要设置表名不区分大小写，则要先执行初始化命令，再启动mysql，不然启动之后lower-case-table-names的值默认为0

• 查看mysql表名是否区分大小写

show variables like 'lower_case_table_names';

• 查看mysql初始默认密码

grep 'temporary password' /var/log/mysqld.log

2019-06-20T09:04:50.727449Z 1 [Note] A temporary password is generated for root@localhost: xuukjN,?q8Y<

初始密码为：xuukjN,?q8Y<

• 使用初始密码登陆mysql

mysql -uroot -p

• 重置初始密码

alter user 'root'@'localhost' identified by '新密码';

• 开启mysql远程连接

mysql -uroot -p

use mysql;

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

flush privileges;

如果在输入初始密码之后，返回Access denied for user 'root'@'localhost'，则可以通过如下操作来解决

1. systemctl stop mysqld
2. systemctl set-environment MYSQLD_OPTS="--skip-grant-tables"
3. systemctl start mysqld
4. mysql -u root
5. flush privileges;
6. alter user 'root'@'localhost' identified by '新密码';
7. delete from user where user = 'root' and host = '%';
8. update user set host = '%' where user = 'root';
9. flush privileges;
10. systemctl stop mysqld
11. systemctl unset-environment MYSQLD_OPTS
12. systemctl start mysqld