<?php

/**
 * Интерфейс драйвера класса баз данных
 */
interface IDatabase
{
    public function connect(array $dsn);
    public function close();
    public function query($query);
    public function fetchAllArray($query);
    public function fetchOneArray($query);
}

abstract class DB implements IDatabase
{
    const limit = 1024;
    protected $db;

    public static function quote($x) 
    {
        return "'" . $x . "'";
    }

    private static function assign_quote($x, $y) 
    {
        return $x . "='" . $y . "'";
    }

    function insert($table, array $values)
    {
        return $this->query("INSERT INTO $table (" . implode(",", array_keys($values)) 
        . ") VALUES (" . implode(",", array_map(array('self', 'quote'), array_values($values))) . ")");
    }

    function update($table, array $values, $cond)
    {
        return $this->query("UPDATE $table SET " . implode(",", 
            array_map(array('self', 'assign_quote'), array_keys($values), array_values($values))) . " WHERE $cond");
    }

    function check_text($text)
    {
        if(strlen($text) > self::limit) $text = substr($text, 0, self::limit);
        $text = htmlspecialchars(trim($text));
        return $text;
    }
}

?>