MySQL User Privileges

Create User:
CREATE USER username IDENTIFIED BY 'password';

ex:
- CREATE USER myuser IDENTIFIED BY 'mypass';
- CREATE USER myuser;


Assign Permission:
GRANT PRIVILEGES_LIST|ALL ON DATABASE[.TABLES|.*] TO 'username'@'HOST';

ex:
- GRANT SELECT,INSERT,UPDATE,DELETE,CREATE,DROP ON mydb TO 'myuser'@'localhost';

List Permission:
SHOW GRANTS FOR 'user'@'host';

ex:
SHOW GRANTS FOR 'admin'@'localhost';

MySql Database backup command - mysqldump

Syntax:
mysqldump [options] -h hostname -u username -p password database|--all-databases [tables] > backupfile.sql

Example:

• mysqldump -h localhost -u root -p test > backup.sql
• mysqldump -h localhost -u root -p test mytable > backup.sql
• mysqldump -h localhost -u root -p --all-databases > backup.sql

Getting Nth highest salary (will work for all databases)

SELECT * FROM employee e1 WHERE (n-1)=(SELECT COUNT(DISTINCT salary) FROM employee  e2 WHERE e2.salary>e1.salary)

*n - Nth highest salary

How to get Latitude and Longitude of a location

• Open maps.google.com.
• Point the position, which latitude and longitude require.
• Place the below JS code in address bar of your browser.

javascript:void(prompt('',gApplication.getMap().getCenter()));

• A popup alert will show you the latitude and longitude of the selected location.

Linux - Useful commands

Search any software and its version:
apt-cache search software_name


Install software:
sudo apt-get install software_name

Install sh file:
sudo sh file_name.sh