[ubuntu] mysql 설치

# 버전확인 

ubuntu@ubuntu:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.4 LTS
Release:        18.04
Codename:       bionic

 

# mysql 설치 

ubuntu@ubuntu:~$ sudo apt-get update
--- 
ubuntu@ubuntu:~$ sudo apt-get install mysql-server-5.7
---
설치 과장 진행. Y 입력. 
---

 

# mysql 설치 확인 

ubuntu@ubuntu:~$ apt --installed list | grep mysql

 

# mysql service 실행 

ubuntu@ubuntu:~$ service mysql start
==== AUTHENTICATING FOR org.freedesktop.systemd1.manage-units ===
Authentication is required to start 'mysql.service'.
Authenticating as: Ubuntu (ubuntu)
Password:
==== AUTHENTICATION COMPLETE ===
ubuntu@ubuntu:~$ ps -ef | grep mysql
mysql     4563     1  0 03:50 ?        00:00:00 /usr/sbin/mysqld --daemonize --pid-file=/run/mysqld/mysqld.pid

 

# mysql root 접속 

$ mysql -u root -p 으로 로그인 시도를하면 
'ERROR 1698 (28000): Access denied for user 'root'@'localhost'이라는 에러를 발생할때가 있다.

 

  - 이는 root 계정이 authsocket 으로 처리 되어있기 때문이다.

  - sudo mysql -u root # sudo를 사용하여 root계정으로 mysql에 접속한다.

 

  - id / passwd 방식으로의 처리를 위해 로 접속하여 비밀번호 방식을 바꿔준다. 

mysql> update user set plugin='mysql_native_password' where user='root';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

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

mysql> select user, host, plugin from user;
+------------------+-----------+-----------------------+
| user             | host      | plugin                |
+------------------+-----------+-----------------------+
| root             | localhost | mysql_native_password |
| mysql.session    | localhost | mysql_native_password |
| mysql.sys        | localhost | mysql_native_password |
| debian-sys-maint | localhost | mysql_native_password |
+------------------+-----------+-----------------------+
4 rows in set (0.00 sec)

mysql> exit
Bye

 

    - mysql_native_password 으로 변경되었으므로 재접속을 시도해 본다.

ubuntu@ubuntu:~$ mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.7.30-0ubuntu0.18.04.1 (Ubuntu)

Copyright (c) 2000, 2020, 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>

 

# root 비밀번호 변경 

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 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> alter user 'root'@'localhost' identified with mysql_native_password by 'mypassword123';

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

 

 

 

# mysql 제거 : 혹시라도 제거할 일이 생긴다면.. ^^

ubuntu@ubuntu:~$ apt --installed list | grep mysql
ubuntu@ubuntu:~$ sudo apt-get purge mysql-server
ubuntu@ubuntu:~$ sudo apt-get purge mysql-common
ubuntu@ubuntu:~$ sudo apt-get purge mysql-server-core-5.7
ubuntu@ubuntu:~$ sudo apt-get purge mysql-client-core-5.7

## 제거 이후 설치 패키지 확인 
ubuntu@ubuntu:~$ apt --installed list | grep mysql


## 파일이 남아 있다면 제거 
sudo rm -rf /var/log/mysql
sudo rm -rf /var/log/mysql.*
sudo rm -rf /var/lib/mysql
sudo rm -rf /etc/mysql