MariaDB (Mysql) のインストール ・コマンド一覧

◆ログイン
mysql -u root -p
オプション： -u
ユーザ名指定
オプション： -p
ログインにパスワードプロンプト要求

( データベース名が該当する箇所は、拡張子 .dbは不要。　名前だけ。）

◆DB一覧表示
show databases;

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |


◆DBの作成
create database データベース名;
MariaDB [(none)]> create database msg;

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| msg                |
| mysql              |
| performance_schema |
+--------------------+
4 rows in set (0.00 sec)

◆DBの削除
DROP DATABASE 　データベース名;

◆使用するDBの指定
use データベース名;

MariaDB [(none)]> use msg


◆レコードを検索する
SELECT * FROM テーブル名;

◆ログアウト
exit;

◆テーブルの一覧表示
show tables;

MariaDB [msg]> show tables;　　♯DBを選択した後で、[ ]内に選択中のDB名
+---------------+
| Tables_in_msg |
+---------------+
| tw_msg        |
+---------------+
1 row in set (0.00 sec)



◆テーブルの内容確認
(use database名でデータベースを指定した後）
select * from テーブル名


1. MariaDBのパッケージを確認 と削除[@ lib]# cd /var/lib
[@ lib]#  rpm -qa | grep maria
mariadb-5.5.60-1.el7_5.x86_64
mariadb-server-5.5.60-1.el7_5.x86_64
mariadb-libs-5.5.60-1.el7_5.x86_64


[@ lib]# yum remove mariadb
============================================================================================================================
 Package                          Arch                     Version                            Repository               Size
============================================================================================================================
Removing:
 mariadb                          x86_64                   1:5.5.60-1.el7_5                   @base                    49 M
Removing for dependencies:
 mariadb-server                   x86_64                   1:5.5.60-1.el7_5                   @base                    58 M

Removed:
  mariadb.x86_64 1:5.5.60-1.el7_5
Dependency Removed:
  mariadb-server.x86_64 1:5.5.60-1.el7_5

Remove  1 Package (+1 Dependent package)
Complete!

[ lib]# yum remove mariadb-libs
Removed:
  mariadb-libs.x86_64 1:5.5.60-1.el7_5
Dependency Removed:
  perl-DBD-MySQL.x86_64 0:4.023-6.el7                             postfix.x86_64 2:2.10.1-6.el7

[root@cnewgwb6 lib]# rpm -qa | grep maria
[root@cnewgwb6 lib]#

[root@cnewgwb6 lib]# ls -a
.    ..
authconfig    dbus    letsencrypt  mysql    php    postfix     selinux    tuned

[@ lib]# rm -rf mysql
[@lib]# ls -a

2. MariaDBの再インストール


[ lib]# yum install mariadb mariadb-server

Installed:
  mariadb.x86_64 1:5.5.60-1.el7_5                           mariadb-server.x86_64 1:5.5.60-1.el7_5
Dependency Installed:
  mariadb-libs.x86_64 1:5.5.60-1.el7_5                          perl-DBD-MySQL.x86_64 0:4.023-6.el7
Complete!

[root@cnewgwb6 lib]# rpm -qa | grep maria
mariadb-5.5.60-1.el7_5.x86_64
mariadb-server-5.5.60-1.el7_5.x86_64
mariadb-libs-5.5.60-1.el7_5.x86_64
[root@cnewgwb6 lib]# ls -a
authconfig    dbus    letsencrypt  mysql  php   postfix     selinux    tuned　<-再びディレクトリが出来ています。


文字コードの設定
[@　lib]# vi /etc/my.cnf

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Settings user and group are ignored when systemd is used.
# If you need to run mysqld under a different user or group,
# customize your systemd unit file for mariadb according to the
# instructions in http://fedoraproject.org/wiki/Systemd
character-set-server=utf8
[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid
#
# include all files from the config directory
#
!includedir /etc/my.cnf.d
サービスの起動
[@　lib]# systemctl enable mariadb.service
Created symlink from /etc/systemd/system/multi-user.target.wants/mariadb.service to /usr/lib/systemd/system/mariadb.service.
[@lib]# systemctl start mariadb.service