dal.php

<?php

class database_abstraction_layer {
  // Store the entire db in memory, but make sure it's inaccesable to the user.
  private $db;
  // This is the file that this DAL will operate on. In MySQL, this will be configs.
  private $file;

  // This is the construct function that is called when the dal object is created.
  public function __construct($file){
    // Store the file name in the object
    $this->file = $file;
    // Load the database
    $this->db = $this->load();
  }

  // Load the database: PRIVATE
  private function load(){
    if (file_exists($this->file)) {
      $dbraw = file_get_contents($this->file);
      if($dbraw == ""){
        die("You are reading from the file too quickly. Re-write this DAL with MySQL in mind.");
      } else {
        $database = unserialize($dbraw);
        if($database === FALSE){
          die("Data will not unserialize. (Database most likely corrupted)");
        } else {
          return $database;
        }
      }
    } else {
      echo "Info: `".$this->file."` file does not exist: initializing.\n";
      return $this->init();
    }
  }

  // Initilize the database. You will want to set up your structure for the game here!
  // To reset the databse, simple delete the db.dat (or whatever $this->file is)
  private function init() {
    // New database object using stdClass
    $database = new stdClass();
    // Array of strings?
    $database->colors= array("Blue","Green","Red","Yellow");
    // A string itself?
    $database->name = "The Magic Rainbow";
    // The time that the db is initialized.
    $database->inittime = time();
    return $database;
  }

  // This is the destruct function that is called when the dal object is destroyed.
  public function __destruct() {
    $this->save();
  }

  // This function saves the DB to file.
  private function save() {
    file_put_contents($this->file,serialize($this->db));
  }

  // This is your first actually accessable function. Keep in mind that these functions need to logically
  // equate to MySQL commands. e.g. if this function updated the number of potatues, it would be
  // "UPDATE users SET potato = \"$value\" WHERE UID = \"$UID\"";
  public function example_update_potato($value){
    $this->db->potato = $value;
  }

  // This is another sample function, just so you can see what data is actually stored in your awesome database.
  public function example_getAllTheData(){
    return $this->db;
  }

}

example.php

#!/usr/bin/php
<?php

// We include the Database Abstraction Layer library
require("dal.php");

// We create a new instance of it, thus automatically calling __construct
$dal = new database_abstraction_layer("db.dat");

// We call a sample function, in this case update potatoes to time.
$dal->example_update_potato( time() );

// Here we print out what's actually in the database. Keep in mind,
// functions like this are bad, as it's hard to translate this into a MySQL function!
print_r($dal->example_getAllTheData());

// This is the end of the script, so the __destruct is automatically called.