虚拟机安装MYSQL后不知道密码打开 ERROR 1698 (28000): Access denied for user ‘root‘@‘localhost‘

yq@gyq-virtual-machine:~$ mysql -u root -p
Enter password: 
ERROR 1698 (28000): Access denied for user 'root'@'localhost'

gyq@gyq-virtual-machine:~$ sudo mysql -u root -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 13
Server version: 8.0.28-0ubuntu0.20.04.3 (Ubuntu)
Copyright (c) 2000, 2022, 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> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.03 sec)
mysql>

mysql -u root -p

set password for 'root'@'localhost'='123';

2022-04-14 09:22:27 INFO  StateStoreCoordinatorRef:54 - Registered StateStoreCoordinator endpoint
Exception in thread "main" java.sql.SQLException: Access denied for user 'root'@'localhost'
    at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:129)
    at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122)
    at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:829)
    at com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:449)
    at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:242)
    at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:198)
    at org.apache.spark.sql.execution.datasources.jdbc.JdbcUtils
anonfun$createConnectionFactory$1.apply(JdbcUtils.scala:63)atorg.apache.spark.sql.execution.datasources.jdbc.JdbcUtils
anonfun$createConnectionFactory$1.apply(JdbcUtils.scala:63)atorg.apache.spark.sql.execution.datasources.jdbc.JdbcUtils
anonfun$createConnectionFactory$1.apply(JdbcUtils.scala:54)
    at org.apache.spark.sql.execution.datasources.jdbc.JDBCRDD$.resolveTable(JDBCRDD.scala:56)
    at org.apache.spark.sql.execution.datasources.jdbc.JDBCRelation.<init>(JDBCRelation.scala:115)
    at org.apache.spark.sql.execution.datasources.jdbc.JdbcRelationProvider.createRelation(JdbcRelationProvider.scala:52)
    at

update user set authentication string='' where user= 'root';
ALTER user 'root' @'localhost' IDENTIFIED BY‘123456';
ALTER USER 'root'@'localhost' IDENTIFIED BY 'QQ3154067760!!!';
use mysql; ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '123456'; flush privileges; quit;
update user set authentication_string='' where user='root';
mysql> flush privileges ;
mysql>quit
2022-04-14T05:34:48.181552Z 6 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: <%2qvHuBt7Bu
MySQL修改初始密码三种方法：
方法一：
1、使用空的初始密码登录mysql账号：
mysql-uroot -p
2、修改root密码：
SETPASSWORD = PASSWORD('123456');
方法二：
1、使用空的初始密码登录mysql账号：
mysql-uroot -p
2、修改root密码：
mysqladmin -u root password '123456'
方法三：
1、使用空的初始密码登录mysql账号：
mysql-uroot -p
2、修改root密码：
mysql> update user set Password=password("123456") where User='root';
Query OK, 4 rows affected (0.01 sec)
Rows matched: 4 Changed: 4 Warnings: 0
mysql> flush privileges;
Query OK, 0 rows affected (0.04 sec)
mysql> select Host,User,password from user where user='root';
+-----------------------+------+-------------------------------------------+
| Host | User | password |
+-----------------------+------+-------------------------------------------+
| localhost | root | *5626ED34B75C6C508BA2A3D0A4F6E4C58823138C |
| localhost.localdomain | root | *5626ED34B75C6C508BA2A3D0A4F6E4C58823138C |
| 127.0.0.1 | root | *5626ED34B75C6C508BA2A3D0A4F6E4C58823138C |
| ::1 | root | *5626ED34B75C6C508BA2A3D0A4F6E4C58823138C |
+-----------------------+------+-------------------------------------------+
4 rows in set (0.00 sec)
mysql 5.7的数据库没有了password字段，用的是authentication_string字段：
mysql> update mysql.user set authentication_string=password('root') where user='root' ;
mysql> flush privileges;
mysql 8.0.13的数据库用的也是authentication_string字段：
mysql> update mysql.user set authentication_string='******' where user='root' ;
mysql> flush privileges;
参考：
https://www.cnblogs.com/jimmyTang-J/p/9698211.html
https://blog.csdn.net/xuheng8600/article/details/80034647
https://blog.csdn.net/z13615480737/article/details/78907697
======================================================================
1页
初始密码为空，使用空密码登陆mysql执行下列语句
mysql>use mysql;
mysql> UPDATE user SET password=PASSWORD(root) WHERE user='root';
mysql> FLUSH PRIVILEGES;
mysql> quit;
修改/opt/lampp/phpmyadmin/config.inc.php
找到如下代码：
$cfg['Servers'][$i]['auth_type'] = 'config';
$cfg['Servers'][$i]['user'] = 'root';
$cfg['Servers'][$i]==================================================================
update user set authentication_string=PASSWORD('123456') where user='root';我个
gyq@gyq-virtual-machine:/etc/mysql$ cat debian.cnf
cat: debian.cnf: 权限不够
gyq@gyq-virtual-machine:/etc/mysql$ sudo cat debian.cnf
[sudo] gyq 的密码： 
# Automatically generated for Debian scripts. DO NOT TOUCH!
[client]
host     = localhost
user     = debian-sys-maint
password = dOv1YXqIEXueQbJL
socket   = /var/run/mysqld/mysqld.sock
[mysql_upgrade]
host     = localhost
user     = debian-sys-maint
password = dOv1YXqIEXueQbJL
socket   = /var/run/mysqld/mysqld.sock
gyq@gyq-virtual-machine:/etc/mysql$ mysql -uroot -p
Enter password: 
ERROR 1698 (28000): Access denied for user 'root'@'localhost'
gyq@gyq-virtual-machine:/etc/mysql$ mysql -u debian-sys-maint -p dOv1YXqIEXueQbJL
Enter password: 
ERROR 1049 (42000): Unknown database 'dOv1YXqIEXueQbJL'
gyq@gyq-virtual-machine:/etc/mysql$ mysql -u debian-sys-maint -p 
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 13
Server version: 8.0.28-0ubuntu0.20.04.3 (Ubuntu)
Copyright (c) 2000, 2022, 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> use mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> update user set authentication_string=PASSWORD("123456") where user='root';
ERROR 1064 (42000): You have an error in your 
-----------------------------------------------------------------------------------------------------------------------------
第一步：进入目录：cd /etc/mysql,查看debian.cnf文件第二步：使用上图中的账号密码登录MySQL。第三步：查看数据库中的库。
第四步：使用mysql库。
第五步：使用一下语句设置账号密码：update user set authentication_string=PASSWORD("自定义新密码") where user='root';我个人设置的简单。账号为：root。
 密码：123456.第六步：执行一下语句：update user set plugin="mysql_native_password";第七步：刷新：flush privileges;第八步：退出：quit；第九步：修改密码完成。
在命令框中输入：/etc/init.d/mysql restart; 重启MySQL
------------------------------------————————————————————————————————————————————————————————————+++
create table user_test (
name varchar(64),
age int(11)
)
CREATE TABLE St(
bname CHAR(10) PRIMARY KEY, 
number CHAR(10)
);