PHP - Call To Undefined Method

Question

I have a PHP class with a few functions defined, this class is responsible for database access:

class database {

    function open($params) {
        // code here to open the db
    }

    function close() {
        // code here to close the db
    }

    function count_users() {
        // code here counts the number of user records

        // Return -1 for testing
        return -1;
    }

    function insert_user($user) {
        // code here inserts a user record
    } 

    function select_user($user_id) {
        // code here selects a user record
    }

}

I have accessor classes defined as follows:

require_once("database.php");

class user {

    public $user_id;
    public $email_address;
    // etc, etc

}

class db_user {

    static function select_user($user_id) {
        $db = new database();
        $db->open();

        $user = NULL;

        $result = $db->select_user($user_id);

        // Test the result and decode user record into $user, etc

        $db->close();

        return $user;
    }

    static function count_users() {
        $db = new database();
        $db->open();

        $count = $db->count_users();

        $db->close();

        return $count;
    }

}

My issue occurs when I attempt to count the number of users through db_user::count_users(); which always fails with a Fatal Error: call to undefined method database::count_users

If I dump the database class methods using get_class_methods , I can see that the count_users function isn't present in the list but I have no idea why.

I'm very much a PHP n00b so there maybe something really obvious I'm not doing. My db_user and user classes have many other functions which pull data back through the database class and all of these succeed - just this one function.

Please help!

---

UPDATE

Ok, so, having removed a couple of functions from the database class and re-uploaded the file to the live server, it appears that it is somehow being "cached" as when I dump the methods belonging to the database object, the removed methods are still displayed in the list.

The count_users function is also not present in the method list yet when I inspect the file uploaded to the server, it is there in code.

Is there any way of removing this caching???

Answer 1

Try as follows:

class user extends database {
   //code user class goes here
}

or

class user extends db_user {
   //code user class goes here
}

simple problem solved.

Answer 2

You can store you instance of Database to the variable.

class db_user {
    public static $db;
    static function openDatabase(){
        self::$db = new database();
        self::$db->open();
    }
    static function select_user($user_id) {

        $user = NULL;

        $result = self::$db->select_user($user_id);

        // Test the result and decode user record into $user, etc

        self::$db->close();

        return $user;
    }

    static function count_users() {

        $count = $db->count_users();

        self::$db->close();

        return $count;
    }

}

Answer 3

The issue, it would appear, is related to another version of the "database.php" file hiding in a sub-folder which must have been copied there by mistake.

Having removed this troublesome file, all now works as expected.

Thanks for your help.

Answer 4

Tried running your code in on-line phptester tool - first complained about missing $params in $db->open() , removing the argument (or passing the $params) it works fine on php 5.2,5.3,5.4. No complaints about count_users() .