接上篇，在服务器上装完mysql8.0.15后，想通过本地的sqlyog工具连接，用户root,初始密码都正确
但是在本地依然报错：
error no. 1045 access denied for user 'root'@'*****' (using password:YES)
注：初始密码的方法：https://blog.csdn.net/liliuqing/article/details/88721881
原来： MySql-Server 出于安全方面考虑默认只允许本机(localhost, 127.0.0.1)来连接访问.
那么必须给root修改远程访问权限！步骤如下：
1.在服务器端定位到D:\server\mysql-8.0.15-winx64\bin,打开dos窗口，输入命令：
mysql -u root -p(注：root表示登录的用户)
2.出现让输入密码，输入密码后回车，登录成功后，出现
E:\opt\mysql\mysql-8.0.15-winx64\bin>mysql -uroot -p
Enter password: ************
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 8.0.15
Copyright (c) 2000, 2019, 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.3.继续输入：use mysql，出现错误，如下：
mysql> use mysql
ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.那么需要更改用户密码，输入命令：
alter user 'root'@'localhost' identified with mysql_native_password by 'amp';
结果如下：
mysql> alter user 'root'@'localhost' identified with mysql_native_password by 'amp';
Query OK, 0 rows affected (0.01 sec)注：在mysql8版本中更改用户密码需要加入with mysql_native_password，并且要加入;所以一下两种写法都是不对的。
alter user 'root'@'localhost' identified by 'amp';
alter user 'root'@'localhost' identified with mysql_native_password by 'amp'
最后要输入flush privileges,刷新数据库。否则会保留在缓存中。结果如下：
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)4.继续输入命令：
use mysql
select host,user from user;
结果如下：
mysql> use mysql
Database changed
mysql> select host,user form user;
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use near 'user'
at line 1
mysql> select host,user from user;
+-----------+------------------+
| host | user |
+-----------+------------------+
| localhost | mysql.infoschema |
| localhost | mysql.session |
| localhost | mysql.sys |
| localhost | root |
+-----------+------------------+
4 rows in set (0.00 sec)果然，发现root用户的访问权限是localhost,需要修改host为%，输入命令：
update user set host='%' where user='root';
flush privileges;
结果如下:
mysql> update user set host='%' where user='root';
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
再次查询修改后结果，OK。结果如下：
mysql> select host,user from user;
+-----------+------------------+
| host | user |
+-----------+------------------+
| % | root |
| localhost | mysql.infoschema |
| localhost | mysql.session |
| localhost | mysql.sys |
+-----------+------------------+
4 rows in set (0.00 sec)解决OK，远程登录开启成功。