<?php

class DB_Element {

	var $data, $id, $table;

	function DB_Element($data, $table) {
		$this->data = $data;
		$this->table = $table;
	}

	function connect($user = 'user', $pwd = 'pwd', $db = 'myDB', $server = '') {
		if (!mysql_connect($server, $user, $pwd)) {
			trigger_error('Could not connect to mysqld.');
			return false;
		}

		if (!mysql_select_db($db)) {
			trigger_error(mysql_error());
			return false;
		}

		return true;
	}

	function getID() {
		return $this->id;
	}

	function read($key) {
		$query = 'SELECT `'.$this->table.'_id`';
		foreach ($this->data as $name => $value) {
			$query .= ', `'.$name.'`';
		}
		$query .= ' FROM `'.$this->table.'` WHERE `'.$key.'`="'.$this->data[$key].'"';

		if (!$result = mysql_query($query)) {
			trigger_error(mysql_error());
			return false;
		}

		if (mysql_num_rows($result) != 1) {
			return false;
		}

		$result = mysql_fetch_assoc($result);

		$this->id = $result[$this->table.'_id'];
		unset($result[$this->table.'_id']);
		return $result;
	}

	function getSetString() {
		$set = 'SET';
		foreach ($this->data as $name => $value) {
			$set .= "\n`".$name.'`="'.$value.'",';
		}
		return substr($set, 0, -1);
	}

	function insert() {
		$query = 'INSERT into `'.$this->table.'` '.$this->getSetString();
		$return = mysql_query($query);
		if ($return && mysql_affected_rows() == 1) {
			$this->id = mysql_insert_id();
		}
		return $return;
	}

	function update() {
		$query = 'UPDATE `'.$this->table.'`
			'.$this->getSetString().'
			WHERE `'.$this->table.'_id`='.$this->id;
		return mysql_query($query);
	}

	function delete() {
		$query = 'DELETE FROM `'.$this->table.'`
			WHERE `'.$this->table.'_id`='.$this->id;
		return mysql_query($query);
	}

	function save($key) {
		$read = $this->read($key);
		if ($read) {
			if ($read != $this->data) {
				return $this->update();
			}
			return true;
		}

		return $this->insert();
	}

}

?>