Fatal error: Uncaught Error: Call to a member function prepare() on null in C:\xampp\htdocs\forum\libraries\Database.php:31
Stack trace:
#0 C:\xampp\htdocs\forum\libraries\Topic.php(26): Database->query('select * from t...')
#1 C:\xampp\htdocs\forum\index.php(13): Topic->getTotalTopics()
#2 {main}
thrown in C:\xampp\htdocs\forum\libraries\Database.php on line 31