ubuntu下mysql8.0.21安装及修改root用户密码

1. 安装

$ sudo apt install mysql-server

2. 登录mysql

查看用户名密码：

$ sudo cat /etc/mysql/debian.cnf 
# Automatically generated for Debian scripts. DO NOT TOUCH!
[client]
host     = localhost
user     = debian-sys-maint
password = HW15YXV24Ionvnad
socket   = /var/run/mysqld/mysqld.sock
[mysql_upgrade]
host     = localhost
user     = debian-sys-maint
password = HW15YXV24Ionvnad
socket   = /var/run/mysqld/mysqld.sock

$ mysql -udebian-sys-maint -pHW15YXV24Ionvnad

3. 修改root密码

修改密码的命令为：

ALTER USER user IDENTIFIED BY 'password';

如:

ALTER USER root@localhost IDENTIFIED BY 'MyPasssword';

但是在我这里不生效，查看user表：

mysql> use mysql;
mysql> SELECT * FROM user \G

发现root用户的plugin字段值为auth_socket而其他用户为caching_sha2_password
执行：

ALTER USER root@localhost IDENTIFIED with caching_sha2_password BY 'MyPasssword';

成功使用新密码登录root.