Warning: mysql_query(): Access denied for user ''@'localhost' (using password: NO) in /home/clearsightdevelo/public_html/codebase/update_vitals.php on line 10

Warning: mysql_query(): A link to the server could not be established in /home/clearsightdevelo/public_html/codebase/update_vitals.php on line 10
Could not execute query:
UPDATE sv_students SET `student_name`='', `password`='', `email`='', `youtube_playlist` = '' WHERE student_id=
MySQL Error:Access denied for user ''@'localhost' (using password: NO)