Mysql Trigger

-- phpMyAdmin SQL Dump
-- version 3.3.9
-- http://www.phpmyadmin.net
--
-- Host: localhost
-- Generation Time: Jun 03, 2014 at 06:07 PM
-- Server version: 5.5.8
-- PHP Version: 5.3.5

SET SQL_MODE="NO_AUTO_VALUE_ON_ZERO";


/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;

--
-- Database: `test`
--

-- --------------------------------------------------------

--
-- Table structure for table `timetase`
--

CREATE TABLE IF NOT EXISTS `timetase` (
  `t_id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `act` varchar(45) NOT NULL,
  `exp` varchar(45) NOT NULL,
  `len` varchar(10) NOT NULL,
  `status` tinyint(1) NOT NULL DEFAULT '0',
  PRIMARY KEY (`t_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=3 ;

--
-- Dumping data for table `timetase`
--

INSERT INTO `timetase` (`t_id`, `act`, `exp`, `len`, `status`) VALUES
(1, '2014-06-03 19:21:39', '2014-06-08 19:21:39', '5', 1),
(2, '2014-06-03 21:59:33', '2014-06-09 21:59:33', '6', 1);

--
-- Triggers `timetase`
--
DROP TRIGGER IF EXISTS `exp_date`;
DELIMITER //
CREATE TRIGGER `exp_date` BEFORE UPDATE ON `timetase`
 FOR EACH ROW BEGIN

IF NEW.status = 1 THEN

IF NEW.act = '' THEN
SET NEW.act=NOW(),NEW.exp=DATE_ADD(NEW.act,INTERVAL NEW.len DAY);
ELSE
SET NEW.act=Old.act,NEW.exp=DATE_ADD(NEW.act,INTERVAL NEW.len DAY);
END IF;

END IF;

END
//
DELIMITER ;