1.解除安裝

完全刪除MySQL 5.7，沒有安裝的朋友可跳過此階段

1. 1 刪除MySQL的相關檔案及其子目錄

sudo apt-get remove mysql-*

1.2 清理殘留的資料

dpkg -l |grep ^rc|awk '{print $2}' |sudo xargs dpkg -P

2. 安裝

  # 安裝mysql服務
  sudo apt-get install mysql-server
  # 安裝客戶端
  sudo apt install mysql-client
  # 安裝依賴
  sudo apt install libmysqlclient-dev
  # 檢查狀態
  sudo netstat -tap | grep mysql
 

3. 配置root密碼

注意：MySQL5.7安裝時不會提示配置密碼和使用者名稱，可通過輸入mysql直接進入，原因：root的plugin被修改成了auth_socket，用密碼登陸的plugin應該是mysql_native_password，直接用root許可權登入就不用密碼,修改root密碼和登入驗證方式

3.1檢視mysql初始的使用者、密碼及登入驗證方式

root> mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
......
mysql> select user, authentication_string,plugin from user;
+------------------+-------------------------------------------+-----------------------+
| user             | authentication_string                     | plugin                |
+------------------+-------------------------------------------+-----------------------+
| root             |  										   | auth_socket |
| mysql.session    | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password |
| mysql.sys        | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password |
| debian-sys-maint | *C58EEC8342F164C89DFA6128785719DE1AC73DAE | mysql_native_password |
+------------------+-------------------------------------------+-----------------------+
4 rows in set (0.00 sec)
 

如上可知mysql初始的root使用者沒有密碼且plugin為auth_socket這種方式

3.2設定密碼和登入驗證方式

mysql> update mysql.user set authentication_string=PASSWORD('123456'), plugin='mysql_native_password' where user='root';
mysql> flush privileges;
mysql> exit
Bye
# exit
$ sudo /etc/init.d/mysql restart
$ mysql -uroot -p

Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 5.7.22-0ubuntu18.04.1 (Ubuntu)

Copyright (c) 2000, 2018, 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> 
 

4. 配置MySQL遠端登入

# 修改配置檔案，註釋掉bind-address = 127.0.0.1
$ sudo vi /etc/mysql/mysql.conf.d/mysqld.cnf

# 儲存退出，然後進入mysql服務，執行授權命令：
$ mysql -uroot -p

mysql> grant all on *.* to [email protected]'%' identified by '123456' with grant option;
Query OK, 0 rows affected, 1 warning (0.00 sec)

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

mysql> exit
Bye
$ sudo /etc/init.d/mysql restart