[root@localhost log]# mysql -u root -p

Enter password:

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 21

Server version: 8.0.15 MySQL Community Server - GPL

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owners.

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mysql> set password='123456';

Query OK, 0 rows affected (0.00 sec)

//或者

mysql> ALTER user 'root'@'localhost' IDENTIFIED BY '123456';

在数据库命令行中输入：ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';