PDOException:SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket

whenever i run the following command php artisan migrate:install, i will get the following error in my ubuntu 12.04 terminal...
[PDOException]
SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket ' /var/run/mysqld/mysqld.sock' (2).

I install laravel 5 in ubuntu 12.04. In my /var/run/mysqld folder, i don't have any mysqld.sock file. Everyone says check out your .env file but i don't have any .env.example file but yes i have app.php, database.php mail.php, cache.php files in my app/config folder.In the whole process i have conclude on thing that their is a problem with connectivity with database because whenever i want to migrate any table in database i will not migrate or not shown in database but i will create table file in my app/controller/http folder. So the problem is table is not displayed in database after i run php artisan migrate command else it will show error above mentioned. So plz help me out. Thankss.......

via Chebli Mohamed