mysql设置初始密码

E:\zhurong_soft\MySQL\MySQL Server 8.1\bin>mysql -uroot
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 29
Server version: 8.1.0 MySQL Community Server - GPL

Copyright (c) 2000, 2023, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql>
mysql> update user set authentication_string='' where user='root';
ERROR 1046 (3D000): No database selected
mysql> update user set authentication_string='' where user='root';
ERROR 1046 (3D000): No database selected
mysql> use mysql;
Database changed
mysql> update user set authentication_string='' where user='root';
Query OK, 0 rows affected (0.00 sec)
Rows matched: 1  Changed: 0  Warnings: 0

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
Query OK, 0 rows affected (0.01 sec)

mysql>