ubuntu can't connect to local mysql server through socket '/var/run/mysqld/mysqld.sock' (2) code example

Example 1: can't connect to local mysql server through socket '/var/run/mysqld/mysqld.sock'

# Start your mysql server
/etc/init.d/mysql start

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

service mysql start