DB.php

<?php

public static function DB($query = null)
{
	static $db = array();
	static $result = array();

	if (isset($db[self::$id], $query) === true)
	{
		if (empty($result[self::$id][$hash = md5($query)]) === true)
		{
			$result[self::$id][$hash] = $db[self::$id]->prepare($query);
		}

		if (is_object($result[self::$id][$hash]) === true)
		{
			if ($result[self::$id][$hash]->execute(self::Flatten(array_slice(func_get_args(), 1))) === true)
			{
				if (preg_match('~^(?:INSERT|REPLACE)\b~i', $query) > 0)
				{
					$sequence = null;

					if (strcmp('pgsql', $db[self::$id]->getAttribute(PDO::ATTR_DRIVER_NAME)) === 0)
					{
						if (preg_match('~\bRETURNING\b~i', $query) > 0)
						{
							return $result[self::$id][$hash]->fetchColumn();
						}

						$sequence = sprintf('%s_id_seq', trim(ph()->Text->Regex($query, 'INTO\s*(["\w]+)', array(1, 0), 'i'), '"'));
					}

					return $db[self::$id]->lastInsertId($sequence);
				}

				else if (preg_match('~^(?:DELETE|UPDATE)\b~i', $query) > 0)
				{
					return $result[self::$id][$hash]->rowCount();
				}

				else if (preg_match('~^(?:CALL|DESC(?:RIBE)?|EXPLAIN|PRAGMA|SELECT|SHOW)\b~i', $query) > 0)
				{
					return $result[self::$id][$hash]->fetchAll(PDO::FETCH_ASSOC);
				}

				return true;
			}
		}

		return false;
	}

	else if (preg_match('~^(?:firebird|mysql|pgsql|sqlite):~', $query) > 0)
	{
		try
		{
			$auth = array_slice(func_get_args(), 1, 2);

			if (preg_match('~^(?:firebird|sqlite):~', $query) > 0)
			{
				$query = preg_replace('~^([^:]+):(?:/{2})?(.+)$~', '$1:$2', $query);
			}

			else if (preg_match('~^(?:mysql|pgsql):~i', $query) > 0)
			{
				$query = preg_replace('~^([^:]+):/{0,2}([^:/]+)(?::(\d+))?/(\w+)/?$~', '$1:host=$2;port=$3;dbname=$4', $query);
			}

			$db[self::$id] = new PDO($query, array_shift($auth), array_shift($auth));

			if (strcmp('mysql', $db[self::$id]->getAttribute(PDO::ATTR_DRIVER_NAME)) === 0)
			{
				self::DB('SET time_zone = ?;', date_default_timezone_get());
				self::DB('SET NAMES ? COLLATE ?;', 'utf8', 'utf8_unicode_ci');
			}

			$db[self::$id]->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
		}

		catch (PDOException $e)
		{
			return false;
		}
	}

	return (isset($db[self::$id]) === true) ? $db[self::$id] : false;
}

I also wanted to mention this code for MySQL prepared statements