How to insert same `datetime` variable into different tables? - php

Question

I'd like to store a datetime variable into different tables by using two functions. I use constraint in CI but still have no luck.
This is the constraint:
$date_now = date("ymdhis");
define('TODAY_DATE',$date_now);
These are the functions:
public function save_activity_m(){
foreach($details as $rows){
$stock_in = $rows['product']."_".TODAY_DATE;
$data['STOCK_IN'] = ($rows['product'] == "") ? NULL : $stock_in;
$this->MProduct->ins_product_m($data);
}
echo "<script type='text/javascript'>alert('New stock arrived');window.top.location.reload();</script>";
}
public function save_notifikasi(){
$lampiran = $this->input->post('lamp');
$data['note_date'] = $lampiran."_".TODAY_DATE;
$data['note'] = $this->input->post('isi');
$this->MProduct->ins_notif($data);
echo "<script type='text/javascript'>alert('You have a notification');</script>";
}
How to make the datetime is the same for $data['STOCK_IN'] and $data['note_date']?

Answer 1

Since the web is stateless, no data in a PHP variable will be held from one page (or load) to another; essentially you're booting the application from scratch each time.
The only way around this is to use some sort of semi-persistent storage such as a cookie or session variable (or persistent storage like the database) - setting a constant, e.g. define('TODAY_DATE',$date_now); will only make that data constant for the current execution of the script(s).
This is a basic example using session storage ($_SESSION):
<?php
// crank up the session
// you may well have one running already,
// in which case ignore this
session_start();
// store the execution time for this script
// as a session variable if it's NOT already set
// i.e. don't overwrite it
if(empty($_SESSION['time_now'])) $_SESSION['time_now'] = date("ymdhis");
public function save_activity_m() {
foreach($details as $rows) {
$stock_in = $rows['product'] . "_" . $_SESSION['time_now'];
$data['STOCK_IN'] = ($rows['product'] == "") ? NULL : $stock_in;
$this->MProduct->ins_product_m($data);
}
echo "<script type='text/javascript'>alert('New stock arrived');window.top.location.reload();</script>";
}
/**
* Assuming this is the last thing you want to
* do with 'time_now' you should unset it here
*/
public function save_notifikasi() {
$lampiran = $this->input->post('lamp');
$data['note_date'] = $lampiran . "_" . $_SESSION['time_now'];
$data['note'] = $this->input->post('isi');
$this->MProduct->ins_notif($data);
// since we're done with the 'time_now' session
// variable we need to unset it...
unset($_SESSION['time_now']);
echo "<script type='text/javascript'>alert('You have a notification');</script>";
}
// just to be on the safe side unset the 'time_now' session var
// if it's older than 1 minute - otherwise future calls to this
// script, by the same user, during the same session will use
// the stored value from $_SESSION['time_now']
if(isset($_SESSION['time_now'])) {
$sessionTime = DateTime::createFromFormat('ymdhis', $_SESSION['time_now']);
$oneMinuteAgoTime = new DateTime('-1 minute');
if($sessionTime < $oneMinuteAgoTime) {
unset($_SESSION['time_now']);
}
}
The caveat is that because you've stored the time in a session variable, unless you update or unset it, it will always be there (for the current session) - so if the user runs the script again it'll just use the stored time from the session.
I've put in a couple of unset() calls to try and work around this.

Answer 2

See PHP: define. It's a constant and it should have the same value if the two functions executed in the same time the script is running.