You don't set $this->dbquery anywhere.
You haven't even defined $dbquery anywhere.
You defined $query, which isn't used anywhere.
You used var $query, instead of private $query, which would be the most optimal choice.
When you disconnect, you disconnect $this->connection, which isn't set anywhere either, NOR defined.
You return your query results, even if it failed.
And lastly, I don't think you should echo ANYTHING AT ALL in your class. Classes are just a way of managing your data. Return DATA instead, and process the data in your controller file(in this case - index.php).
PHP Code:
if($query) // meaning if it returned true
{
echo 'Query successful!';
}
else
{
echo 'Query failed..';
}
Just my opinion