Question

I had 2 Class in PHP That i want to use with each other, but the Class in 2 different PHP Script like clothing_product.php and database.php. It look like this Below:

database.php:

require_once('config.php');

class MySqlDatabase
{
    private $connection;
    private $last_query;
    private $magic_quotes_active;
    private $real_escape_string_exist;

        function __construct(){
            $this->open_connection();
            $this->magic_quotes_active = get_magic_quotes_gpc();
            $this->real_escape_string_exist = function_exists("mysql_real_escape_string");

        }

        private function open_connection()
        {

            $this->connection = mysql_connect(DB_SERVER,DB_USER,DB_PASS);
            if (!$this->connection){
                die("Connection failed!". mysql_error());
            }
            else{
                $db_select = mysql_select_db(DB_NAME);
                if(!$db_select){
                    die("Select database failed". mysql_error());
                }
            }

        }

        public function query($sql){

            $this->last_query = $sql;
            $result = mysql_query($sql,$this->connection);

            $this->confirm_query($result);
            return $result;

        }

        public function confirm_query($result){
            if(!$result){
                $output = "Database query failed: " . mysql_error()."<br /><br />";
                $output.= "Last query that fail is:" . $this->last_query;
                die($output);
            }
        }

        private function escape_value($value) {

            if ($this->real_escape_string_exist) {
                if($this->magic_quotes_active) {$value = stripslashes($value);}
                $value = mysql_real_escape_string($value);
            }
            else {
                if (!$this->magic_quotes_active) {$value = addslashes($value);}
            }
            return $value;
        }

        public function fect_array($result){
            return mysql_fetch_array($result);
        }

        public function num_rows($result){
            return mysql_num_rows($result);
        }

        public function last_id(){
            return mysql_insert_id($this->connection);
        }

        public function affected_rows(){
            return mysql_affected_rows($this->connection);
        }

        public function close_connection(){
            if(isset($this->connection)){
                mysql_close($this->connection);
                unset($this->connection);
            }
        }

}

//$db = new MySqlDatabase();

clothing_product.php:

include(‘../database.php’);

class Clothing_Product {

    public $db = new MySqlDatabase();

        public static function test(){
            echo "Static call successfull";
            return "Static call successfull";
        }


    }

The problem is when i try to USE ‘Public $db = new MySqlDatabase();’ in class clothing_product i get Error. I think the problem is maybe i got a wrong call. Please help me cuz m a noob thnk.

Answer 1

You can’t initialize member variables to anything that is not static, and you’re trying to create an object here:

public $db = new MySqlDatabase();

From the manual:

This declaration may include an initialization, but this
initialization must be a constant value–that is, it must be able to
be evaluated at compile time and must not depend on run-time
information in order to be evaluated.

The workaround is to set your variable in the constructor:

public $db;
public function __construct() { 
    $this->db = new MySqlDatabase();
}