SQL-DATABASE ERROR

Database error in WoltLab Burning Board (): Link-ID == false, connect failed
mysql error: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)
mysql error number: 2002
mysql version: unknown
php version: 5.4.4-14+deb7u8
Date: 24.04.2014 @ 10:51
Script: /wbb2/calendar.php?month=&year=2014
Referer: