Basic management of mysql database in Linux system

MariaDB basic information

1. Start service: systemctl start mariadb
2. Default port number: 3306
3. Main configuration file: vim /etc/my.cnf.d/mariadb-server.cnf
4. Data directory: /var/lib/mysql (you need to clean this directory and backup when you need to reinstall mariadb)
5. Service startup script: /usr/lib/system/mariadb.service

Installation of MariaDB database

MariaDB database management system is a fork of MySql which is designed to be fully compatible with MySql, including API and command line.

• Install the database: dnf install mariadb-server.x86_64
  
• View the file of the mariadb installation package: rpm -ql mariadb-server
  
• Enable database: systemctl enable --now mariadb
  
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Safe initialization of database

1. For the database that has just been installed, you need to set the database password first

• Initialization script: mysql_secure_installation
  
  
• Log in to the database: mysql -uusername -ppassword
  

2. Close the open port of the database

• View the data port number: netstat -antlupe | grep mysql
  By default, the database opens the port to the outside world
  
• Edit the configuration file and close the port: vim /etc/my.cnf.d/mariadb-server.cnf
  
• Restart the mariadb service: systemctl restart mariadb.service

Basic management of the database

• Part of the basic syntax
  

Database Password Management

1. Database password change: mysqladmin -uroot -pwestos password redhat
   
2. Database password cracking
   Close the database: systemctl stop mariadb
   Skip the authorization table to run the database: mysqld_safe --skip-grant-tables &
   Log in to the database: mysql -uroot -pwestos
   View aboutmysql process: ps -aux |grep mysql
   Kill process: kill -9 process number
   New password login: mysql -uroot -plyx
   

User Management

• New User
  

• Ordinary user authorization
  Super user login database: mysql -uroot -pwestos
  

• Test if authorization is successful
  

• Cancel authorization: revoke insert on database_name.* from [email protected]
  

Database Backup and Restore

• Database Backup
  
• Database Restoration
  
• Restore successfully