rpm方式安装MySQL后在命令行登录报错：ERROR 1045 (28000): Unknown error 1045

1.通过https://mirrors.tuna.tsinghua.edu.cn镜像源安装了MySQL5.7.22

rpm -ivh --force --nodeps https://mirrors.tuna.tsinghua.edu.cn/mysql/yum/mysql57-community-el7/mysql-community-client-5.7.22-1.el7.x86_64.rpm

rpm -ivh --force --nodeps https://mirrors.tuna.tsinghua.edu.cn/mysql/yum/mysql57-community-el7/mysql-community-server-5.7.22-1.el7.x86_64.rpm

2.通过/etc/my.cnf配置文件找到MySQL的错误日志存在/var/log/mysql.log里，在该日志里查找到mysql的root用户的临时登录密码

[root@ip-172-31-34-225 log]# cat /var/log/mysqld.log | grep 'temporary password'
2019-02-13T10:32:25.917190Z 1 [Note] A temporary password is generated for root@localhost: a1+J)%zhEURa

3.用临时密码通过命令行登录报错：ERROR 1045 (28000): Unknown error 1045

4.原因是密码错误,参考链接https://blog.csdn.net/nicolelili1/article/details/78833667（为什么初始的临时密码是错误的？这个还没弄明白）

vim /etc/my.cnf

skip-grant-tasbles #添加本行内容，意思是跳过授权表实现免密登录

5.systemctl restart mysqld

6.在命令行输入mysql回车即可登录，登录后设置新的root密码，下次通过新的密码即可登录

mysql> update user set authentication_string = password('XXXXXX') where user = 'root';
Query OK, 1 row affected, 1 warning (0.00 sec)

mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

7.vim /etc/my.cnf

#skip-grant-tables #为提高安全性，将该行注释然后重启mysql.