ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run code example

Example 1: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

sudo apt-get install mysql-server

Example 2: ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)

For mac:
The mysql server is not running.

brew services mysql start