MySQLのインストール

カテゴリ:データベース

CentOS/Ubuntu 両対応

MySQLのインストール

MySQLをインストールします。

CentOS 7 の場合:(リポジトリの追加が必要)

# rpm -ivh http://dev.mysql.com/get/mysql57-community-release-el7-8.noarch.rpm
# yum -y install mysql-community-server

CentOS 8 以降の場合:

# dnf -y install mysql-server

Ubuntu の場合:

# apt -y install mysql-server

MySQLの自動起動を有効にします。

CentOS の場合:

# systemctl enable mysqld

Ubuntu の場合:

# systemctl enable mysql

MySQLの初期設定

MySQLを開始すると自動でデータベースの初期化を行ってくれます。

CentOS の場合:

# systemctl start mysqld

Ubuntu の場合:

# systemctl start mysql

初期設定ではパスワード無しでrootユーザーでログインできる状態になっています。

# mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 13
Server version: 8.0.21 Source distribution

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>

Ubuntu の場合も同様です。

# mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 9
Server version: 8.0.26-0ubuntu0.20.04.2 (Ubuntu)

Copyright (c) 2000, 2021, 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>

この状態はセキュアではないため、以下のコマンドでrootユーザーのパスワードを設定します。

ALTER USER 'root'@'localhost' IDENTIFIED BY 'password';

例)

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'password';
Query OK, 0 rows affected (0.01 sec)
もしくは以下のスクリプトを実行して、対話式で初期設定を実施します。
このスクリプトでは、rootのパスワード設定の他、接続をlocalhostのみに制限したり、初期設定で存在するtestデータベースの削除等が実施できます。
# /usr/bin/mysql_secure_installation




NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MySQL
      SERVERS IN PRODUCTION USE!  PLEASE READ EACH STEP CAREFULLY!


In order to log into MySQL to secure it, we'll need the current
password for the root user.  If you've just installed MySQL, and
you haven't set the root password yet, the password will be blank,
so you should just press enter here.

Enter current password for root (enter for none):
OK, successfully used password, moving on...

Setting the root password ensures that nobody can log into the MySQL
root user without the proper authorisation.

You already have a root password set, so you can safely answer 'n'.

Change the root password? [Y/n] y
New password:
Re-enter new password:
Password updated successfully!
Reloading privilege tables..
... Success!


By default, a MySQL installation has an anonymous user, allowing anyone
to log into MySQL without having to have a user account created for
them.  This is intended only for testing, and to make the installation
go a bit smoother.  You should remove them before moving into a
production environment.

Remove anonymous users? [Y/n] y
... Success!

Normally, root should only be allowed to connect from 'localhost'.  This
ensures that someone cannot guess at the root password from the network.

Disallow root login remotely? [Y/n] y
... Success!

By default, MySQL comes with a database named 'test' that anyone can
access.  This is also intended only for testing, and should be removed
before moving into a production environment.

Remove test database and access to it? [Y/n] y
- Dropping test database...
... Success!
- Removing privileges on test database...
... Success!

Reloading the privilege tables will ensure that all changes made so far
will take effect immediately.

Reload privilege tables now? [Y/n] y
... Success!

Cleaning up...



All done!  If you've completed all of the above steps, your MySQL
installation should now be secure.

Thanks for using MySQL!

「Access denied for user 'root'@'localhost'」が表示される場合

もしrootのパスワードの入力時に「Access denied for user 'root'@'localhost'」が表示される場合、以下のようにオプションを付けてセーフモードで MySQL を起動しなおし、スクリプトを実行してください。

CentOS の場合:

# systemctl stop mysqld
# mysqld_safe --skip-grant-tables &
# /usr/bin/mysql_secure_installation

Ubuntu の場合:

# systemctl stop mysql
# mysqld_safe --skip-grant-tables &
# /usr/bin/mysql_secure_installation

スクリプトの実行後は以下のコマンドで MySQL を通常モードで起動しなおします。

CentOS の場合:

# systemctl restart mysqld

Ubuntu の場合:

# systemctl restart mysql

MySQLに接続できることを確認します。
以下のように"mysql>"が表示されればログイン成功です。

# mysql -u root -p
Enter password:
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 13
Server version: 8.0.21 Source distribution

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>

※終了するときは \q を入力します。

公開日時:2014年07月20日 09:33:59
最終更新日時:2021年08月21日 07:34:19

なお、VPS選びで迷ったら、こちらの記事で主要VPSのメモリ容量ごとの月額、年額料金を比較していますので、是非参考にしてみてください。

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