calling a function from php class

Question

i have witten this php class, but i have problem using it,

<?php
    class cs_mysql{
        protected $configPath;
        protected $db;
        function __construct($cP = null){
            $this->configPath = $cP;
            require $this->configPath;
        }
        private function connection(){
            $db = new mysqli(Config::get('dbHost'),Config::get('dbUser'),Config::get('dbPass'),Config::get('dbName'));
        }
        public function getRow($table){
            $query = 'SELECT * FROM $table ORDER BY `id` DESC';
            $sql = $this->db->query($query);
            if(!$sql){
                echo "FALSE";
            }
        }
    }
?>

i don't know how to run db query : $sql = $this->db->query($query);

Answer 1

Change

$db = new mysqli(Config::get('dbHost'),Config::get('dbUser'),Config::get('dbPass'),Config::get('dbName'));

to

$this->db = new mysqli(Config::get('dbHost'),Config::get('dbUser'),Config::get('dbPass'),Config::get('dbName'));

$db is a property of the class. To access class properties (and methods) you have to reference the class instance using $this .