自mysql5.7之后初始密码不再默认为空

1.查看初始密码：

[root@01 yum.repos.d]# grep 'temporary password'  /var/log/mysqld.log 
2017-03-12T12:25:43.090102Z 1 [Note] A temporary password is generated for root@localhost: h6&%pgp/+BBl

即初始密码为 h6&%pgp/+BBl （密码是随机产生的，每台机器产生的都不一样哦）
如果没有日志文件，先启动mysql程序。

2.登录及修改密码：

[root@01 yum.repos.d]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.7.17

Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved.

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> show databases;
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

登录之后 第一步必须先修改密码，否则其他操作都执行不了。

修改密码的方法：

mysql> alter user root@localhost identified by 'passwd';
Query OK, 0 rows affected (0.00 sec)

新修改的密码中 必须包含 大小写字母数字及符号