1 MySQL8.0安装
sudo apt install mysql-server
1.1 启动MySQL服务
WSL子系统Ubuntu中不包含systemctl命令，使用service命令
# 查看MySQL服务运行状态
sudo service mysql status
* MySQL is stopped.
#启动MySQL服务
sudo service mysql start
* Starting MySQL database server mysqld
* su: warning: cannot change directory to /nonexistent: No such file or directory [ OK ]
查看MySQL是否启动成功
ps -ef | grep mysql
mysql 13613 120 0 15:49 ? 00:00:00 /bin/sh /usr/bin/mysqld_safe
mysql 13760 13613 0 15:49 ? 00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib/mysql/plugin --log-error=/var/log/mysql/error.log --pid-file=ZHOU-PC.pid
zhou 13828 121 0 15:51 pts/0 00:00:00 grep --color=auto mysql
sudo service mysql status
* /usr/bin/mysqladmin Ver 8.0.28-0ubuntu0.20.04.3 for Linux on x86_64 ((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.
Server version 8.0.28-0ubuntu0.20.04.3
Protocol version 10
Connection Localhost via UNIX socket
UNIX socket /var/run/mysqld/mysqld.sock
Uptime: 3 hours 1 min 31 sec
Threads: 2 Questions: 8 Slow queries: 0 Opens: 117 Flush tables: 3 Open tables: 36 Queries per second avg: 0.000
1.2 MySQL登录
mysql -u root -p
Enter password:
ERROR 1698 (28000): Access denied for user 'root'@'localhost'
1.2.1 第一种登录方法
root用户没有设置密码，不能从本地登录，可以使用sudo命令进入，此时不需要输入密码即可进入
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>
1.2.2 第二种登录方法
MySQL在安装时会创建很多默认用户，其中就包含一个 debian-sys-maint，并且创建了该用户的随机密码，存储该用户信息的文件位于 /etc/mysql/debian.cnf文件中。
tree /etc/mysql
.
├── conf.d
│ ├── mysql.cnf
│ └── mysqldump.cnf
├── debian-start
├── debian.cnf
├── my.cnf -> /etc/alternatives/my.cnf
├── my.cnf.fallback
├── mysql.cnf
└── mysql.conf.d
├── mysql.cnf
└── mysqld.cnf
sudo cat debian.cnf
# Automatically generated for Debian scripts. DO NOT TOUCH!
[client]
host = localhost
user = debian-sys-maint
password = YEd1uhCL4DsN5NBD
socket = /var/run/mysqld/mysqld.sock
[mysql_upgrade]
host = localhost
user = debian-sys-maint
password = YEd1uhCL4DsN5NBD
socket = /var/run/mysqld/mysqld.sock
可以利用debian-sys-main用户登录MySQL
mysql -u debian-sys-maint -pYEd1uhCL4DsN5NBD
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 14
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>
1.3 更改root用户密码
MySQL中用户相关信息存储于mysql数据库中，需要现转换到mysql数据库，分别用到如下命令
show databases; use database_name; show tables;
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| sys |
+--------------------+
4 rows in set (0.01 sec)
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> show tables;
+------------------------------------------------------+
| Tables_in_mysql |
+------------------------------------------------------+
| columns_priv |
| component |
| db |
| default_roles |
| engine_cost |
| func |
| general_log |
| global_grants |
| gtid_executed |
| help_category |
| help_keyword |
| help_relation |
| help_topic |
| innodb_index_stats |
| innodb_table_stats |
| password_history |
| plugin |
| procs_priv |
| proxies_priv |
| replication_asynchronous_connection_failover |
| replication_asynchronous_connection_failover_managed |
| replication_group_configuration_version |
| replication_group_member_actions |
| role_edges |
| server_cost |
| servers |
| slave_master_info |
| slave_relay_log_info |
| slave_worker_info |
| slow_log |
| tables_priv |
| time_zone |
| time_zone_leap_second |
| time_zone_name |
| time_zone_transition |
| time_zone_transition_type |
| user |
+------------------------------------------------------+
37 rows in set (0.00 sec)
存储用户相关信息的内容位于user表格中，可以查看表格结构
mysql> desc user;
+--------------------------+-----------------------------------+------+-----+-----------------------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------------------------+-----------------------------------+------+-----+-----------------------+-------+
| Host | char(255) | NO | PRI | | |
| User | char(32) | NO | PRI | | |
| Select_priv | enum('N','Y') | NO | | N | |
| Insert_priv | enum('N','Y') | NO | | N | |
| Update_priv | enum('N','Y') | NO | | N | |
| Delete_priv | enum('N','Y') | NO | | N | |
| Create_priv | enum('N','Y') | NO | | N | |
| Drop_priv | enum('N','Y') | NO | | N | |
| Reload_priv | enum('N','Y') | NO | | N | |
| Shutdown_priv | enum('N','Y') | NO | | N | |
| Process_priv | enum('N','Y') | NO | | N | |
| File_priv | enum('N','Y') | NO | | N | |
| Grant_priv | enum('N','Y') | NO | | N | |
| References_priv | enum('N','Y') | NO | | N | |
| Index_priv | enum('N','Y') | NO | | N | |
| Alter_priv | enum('N','Y') | NO | | N | |
| Show_db_priv | enum('N','Y') | NO | | N | |
| Super_priv | enum('N','Y') | NO | | N | |
| Create_tmp_table_priv | enum('N','Y') | NO | | N | |
| Lock_tables_priv | enum('N','Y') | NO | | N | |
| Execute_priv | enum('N','Y') | NO | | N | |
| Repl_slave_priv | enum('N','Y') | NO | | N | |
| Repl_client_priv | enum('N','Y') | NO | | N | |
| Create_view_priv | enum('N','Y') | NO | | N | |
| Show_view_priv | enum('N','Y') | NO | | N | |
| Create_routine_priv | enum('N','Y') | NO | | N | |
| Alter_routine_priv | enum('N','Y') | NO | | N | |
| Create_user_priv | enum('N','Y') | NO | | N | |
| Event_priv | enum('N','Y') | NO | | N | |
| Trigger_priv | enum('N','Y') | NO | | N | |
| Create_tablespace_priv | enum('N','Y') | NO | | N | |
| ssl_type | enum('','ANY','X509','SPECIFIED') | NO | | | |
| ssl_cipher | blob | NO | | NULL | |
| x509_issuer | blob | NO | | NULL | |
| x509_subject | blob | NO | | NULL | |
| max_questions | int unsigned | NO | | 0 | |
| max_updates | int unsigned | NO | | 0 | |
| max_connections | int unsigned | NO | | 0 | |
| max_user_connections | int unsigned | NO | | 0 | |
| plugin | char(64) | NO | | caching_sha2_password | |
| authentication_string | text | YES | | NULL | |
| password_expired | enum('N','Y') | NO | | N | |
| password_last_changed | timestamp | YES | | NULL | |
| password_lifetime | smallint unsigned | YES | | NULL | |
| account_locked | enum('N','Y') | NO | | N | |
| Create_role_priv | enum('N','Y') | NO | | N | |
| Drop_role_priv | enum('N','Y') | NO | | N | |
| Password_reuse_history | smallint unsigned | YES | | NULL | |
| Password_reuse_time | smallint unsigned | YES | | NULL | |
| Password_require_current | enum('N','Y') | YES | | NULL | |
| User_attributes | json | YES | | NULL | |
+--------------------------+-----------------------------------+------+-----+-----------------------+-------+
51 rows in set (0.00 sec)
mysql> select user,host,plugin from user;
+------------------+-----------+-----------------------+
| user | host | plugin |
+------------------+-----------+-----------------------+
| debian-sys-maint | localhost | caching_sha2_password |
| mysql.infoschema | localhost | caching_sha2_password |
| mysql.session | localhost | caching_sha2_password |
| mysql.sys | localhost | caching_sha2_password |
| root | localhost | auth_socket |
+------------------+-----------+-----------------------+
5 rows in set (0.00 sec)bash
MySQL8.0 中用户默认认证方式为 caching_sha2_password，虽然安全性有保障，但是对于使用本地或者远程连接都造成了一定困扰。因此可以将用户认证方式改为MySQL5.X常用的mysql_native_password方式，只有此种方式才能在MySQL8.0中更改用户密码。
mysql> alter user 'root'@'localhost' identified with mysql_native_password by '0';
Query OK, 0 rows affected (0.01 sec)
1.4 刷新缓存
输入flush privileges,刷新数据库。否则会保留在缓存中。
mysql> flush privileges;
Query OK, 0 rows affected (0.02 sec)
1.5 重启MySQL服务
退出mysql环境可以通过Ctrl+D或者输入quit退出回到Ubuntu环境。
mysql> ^DBye
mysql> quit
Bye
重新进入mysql环境就可以不用sudo在前面，直接使用mysql -u root -p即可
mysql -u root -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 10
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> ;
重复上面的操作可以查看root用户认证方式
mysql> select user,host,plugin from user;
+------------------+-----------+-----------------------+
| user | host | plugin |
+------------------+-----------+-----------------------+
| debian-sys-maint | localhost | caching_sha2_password |
| mysql.infoschema | localhost | caching_sha2_password |
| mysql.session | localhost | caching_sha2_password |
| mysql.sys | localhost | caching_sha2_password |
| root | localhost | mysql_native_password |
+------------------+-----------+-----------------------+
5 rows in set (0.00 sec)
此时的root用户认证已经改为mysql_native_password方式。
1.6 设置root用户的远程访问
此时root用户的host属性仍然是localhost，也就是只能从本地访问，因此可以将root用户的访问权限由本地改为本地和外部都可以访问，将host的值由localhost改为 %。
mysql> update user set user.host='%' where user.user='root';
Query OK, 1 row affected (0.01 sec)
Rows matched: 1 Changed: 1 Warnings: 0
输入flush privileges,刷新数据库。否则会保留在缓存中。
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
mysql> select user,host,plugin from user;
+------------------+-----------+-----------------------+
| user | host | plugin |
+------------------+-----------+-----------------------+
| root | % | mysql_native_password |
| debian-sys-maint | localhost | caching_sha2_password |
| mysql.infoschema | localhost | caching_sha2_password |
| mysql.session | localhost | caching_sha2_password |
| mysql.sys | localhost | caching_sha2_password |
+------------------+-----------+-----------------------+
5 rows in set (0.00 sec)
此时root用户的host访问权限已经改为本地和外部都可以。
重启MySQL服务，即可实现远程连接。
WSL中的Ubuntu子系统访问可以直接使用127.0.0.1或localhost进行访问，
1.7 修改MySQL配置文件实现真正的远程访问
此时使用127.0.0.1或者localhost连接都没有问题，但是在外部一旦换成Ubuntu真正的IP地址访问就会报错。
这时还需要修改MySQL配置文件中的相关配置项 /etc/mysql//mysql.conf.d/mysqld.cnf
修改 bind-address = 0.0.0.0 。
重启MySQL后，再次通过IP地址远程连接。
2 MySQL8.0卸载
sudo apt purge mysql-*
sudo rm -rf /etc/mysql/ /var/lib/mysql
sudo apt autoremove
sudo apt autoclean