Here are a few title options, focusing on the question format and capturing the essence of the article: * **How to Determine User Availability in PHP/MySQL:** This is a straightforward and clear titl

Determining User Availability in PHP/MySQL

When a user logs in, updating a database field can provide an efficient way to monitor their online status. By periodically querying this field, you can determine whether a user is currently active.

Implementation Details

To achieve this:

1. Create a field in the Users table called lastActiveTime.
2. When a user accesses a page, update lastActiveTime with the current server time using MySQL's NOW() function.

Identifying Online Users

To identify online users:

1. Perform a COUNT query for all users with lastActiveTime within the last 5 minutes.
2. Users with a lastActiveTime outside this 5-minute window can be considered offline.

Enhancing Accuracy (Optional)

For near real-time updates on user activity:

1. Create a JavaScript function to ping the server every 60 seconds.
2. The server-side script will update the lastActiveTime field, ensuring continuous tracking of user presence.

Code Examples

Original 2009 Code:

<code class="javascript">var stillAlive = setInterval(function () {
    /* XHR back to server
       Example uses jQuery */
    $.get("stillAlive.php");
}, 60000);</code>

Updated 2022 Code:

<code class="javascript">(async function ping() {
    // Asynchronously call stillAlive.php
    await fetch("stillAlive.php");
    // Issue this call again in 60 seconds
    setTimeout(ping, 60_000);
}());</code>

By implementing this approach, you can reliably determine user online status in PHP/MySQL. It avoids time zone complexities and provides a scalable solution for tracking active users on your website.

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