php mysql last visit - php

Question

I have website where the user can show his last visit to the website every time he logs in.
the type of last_activity column in the database is 'time'.
I made a code that shows the current date and save it in a variable $currentDate
and then set variable $currentDate into last_activity column in the database and update the column every time the user logs in.
but when I test the code I get this result:
your last visit: 00:00:00
the type of last_activity column in the database is 'time'.
here is my code:
<?php
session_start();
include('db.php');
date_default_timezone_set('Asia/Riyadh');
$currentDate = date('m/d/Y h:i:s a', time());
if(isset($_SESSION['Email']) === true)
{
mysql_query("UPDATE `table` SET `lastactivity` = ".$currentDate." WHERE email = '".$_SESSION['Email']."'");
$query = "SELECT * FROM `table` WHERE email = '".$_SESSION['Email']."'";
$run = mysql_query($query);
while($row = mysql_fetch_array($run))
{
$name = $row[1];
$active = $row[10];
echo 'welcome '.$name;
echo 'your last visit '.$active;
;

Answer 1

You should use the type DATETIME or TIMESTAMP to store a datetime value instead of TIME. The TIME datatype has no notion of dates:
The TIME Type
MySQL retrieves and displays TIME values in 'HH:MM:SS' format (or
'HHH:MM:SS' format for large hours values). TIME values may range from
'-838:59:59' to '838:59:59'.
...
Invalid TIME values are converted to '00:00:00'.
Because of that you get
your last visit: 00:00:00
back from the database as your output.
The DATE, DATETIME, and TIMESTAMP Types
The DATETIME type is used for values that contain both date and time
parts. MySQL retrieves and displays DATETIME values in 'YYYY-MM-DD
HH:MM:SS' format. The supported range is '1000-01-01 00:00:00' to
'9999-12-31 23:59:59'.
Edit:
TIMESTAMP and in newer MySQL versions DATETIME columns have nice features, i.e. automatic update:
Automatic Initialization and Updating for TIMESTAMP and DATETIME
As of MySQL 5.6.5, TIMESTAMP and DATETIME columns can be automatically
initializated and updated to the current date and time (that is, the
current timestamp). Before 5.6.5, this is true only for TIMESTAMP, and
for at most one TIMESTAMP column per table.
Edit 2:
Furthermore produces
$currentDate = date('m/d/Y h:i:s a', time());
no valid format of an DATETIME literal. You could use STR_TO_DATE() to convert your value to DATETIME, but I wouldn't recommend this. Better you change your UPDATE statement using the MySQL function NOW() to:
mysql_query("UPDATE `table` SET `lastactivity` = NOW() WHERE email = '".$_SESSION['Email']."'");
You can format your DATETIME value, while retrieving it from MySQL with DATE_FORMAT() and give this computed column a name:
$query = "SELECT *, DATE_FORMAT(lastactivity, '%m/%d/%Y %h:%i%s %p') as last_activity FROM `table` WHERE email = '".$_SESSION['Email']."'";
$run = mysql_query($query);
while($row = mysql_fetch_array($run))
{
$name = $row[1];
$active = $row["last_activity"]; // access to the column by column name
// ...
Note
I recommend to switch from the deprecated mysql_* functions to PDO or mysqli with prepared statements and placeholders instead of concatenation of an sql statement.