Skip to main content

MySQL: Notes

Illustrated: MySQL Logo

Ways to check MySQL version

mysql --version
mysql -V
dpkg -l 'mysql-sever'
mysql -u root -p
How to check MySQL version: mysql --version
How to check MySQL version: mysql --version

Database folder

On Microsoft Windows, by default, MySQL save databases in this folder:

%ProgramData%\MySQL\MySQL Server 5.5\data

Check databases' size

SELECT table_schema AS "Database name", SUM(data_length + index_length) / 1024 / 1024 AS "Size (MB)" FROM information_schema.TABLES GROUP BY table_schema;

Export database schema

$ mysqldump -u root -p --no-data wordpress1001 > c:\backup\schema-wordpress1001.sql
Enter password: ****************

Create a dedicated user to backup databases

Give credit to: http://www.fromdual.com/privileges-of-mysql-backup-user-for-mysqldump

Create dedicated mysql user and grant privileges to run backup

$ mysql -u root -p
CREATE USER 'backupdb'@'localhost' IDENTIFIED BY 'passwordhere';
GRANT SELECT,SHOW VIEW,RELOAD,REPLICATION CLIENT,EVENT,TRIGGER ON *.* TO 'backupdb'@'localhost';
GRANT LOCK TABLES ON *.* TO 'backupdb'@'localhost';
FLUSH PRIVILEGES;
QUIT;

Backup all databases

mysqldump -u backupdb -p --all-databases | gzip -c > /backup/databases-$(date '+%Y%m%d%H%M').sql.gz
Backup all databases using dedicated mysql user backupdb
Backup all databases using dedicated mysql user backupdb

Check databases' size

$ mysql -u root -p
SELECT table_schema AS "Database", 
ROUND(SUM(data_length + index_length) / 1024 / 1024, 2) AS "Size(MB)" 
FROM information_schema.TABLES 
GROUP BY table_schema;

Change user's password

ALTER USER 'username'@'localhost' IDENTIFIED BY 'Enter-new-password';

MySQL/MariaDB Client

apt install mycli

MySQL Shell for VS Code

Popular posts from this blog

Powershell: Get-ChildItem

List, search/find files and directories with Get-ChildItem cmdlet.

Linux command: Check Current Shell

What is your current shell ?

Java: Free Online Courses

The Java™ Tutorials by Oracle The Java Tutorials are practical guides for programmers who want to use the Java programming language to create applications. They include hundreds of complete, working examples, and dozens of lessons. Groups of related lessons are organized into "trails". https://docs.oracle.com/javase/tutorial/ Learn to Program in Java at edX.ogr Get started on the path to becoming a software engineer by learning core coding skills in Java—one of the most popular programming languages. https://www.edx.org/course/learn-to-program-in-java-0 Java Tutorial by javapoint.com https://www.javatpoint.com/java-tutorial Java Tutorial by SoloLearn.com I love SoloLearn because I can learn Java - and other popular programming languages - anywhere, any time on your mobile devices. https://www.sololearn.com/Course/Java/ Java on Azure https://docs.microsoft.com/en-us/learn/paths/java-on-azure/