Faild to connectSQLSTATE[28000] [1045] Access denied for user 'root'@'localhost' (using password: NO) Blog

Fatal error: Uncaught Error: Call to a member function prepare() on null in /home/nlgt42yvb3g2/public_html/include/function.php:36 Stack trace: #0 /home/nlgt42yvb3g2/public_html/blog.php(6): getCounts('articles', '') #1 {main} thrown in /home/nlgt42yvb3g2/public_html/include/function.php on line 36