Question

how can I automatically add the value of a database row (PHP), to the page, without refreshing the page itself, when the mysql database table changes?

So, it is a bit like this: Automatically refresh browser in response to file system changes? , but instead of refreshing the browser with the file system changes, update the content, without refreshing anything, when the databse changes.

Thanks. I have tried to make this as clear as possible.

Answer 1

Please note this is outdated answer. Recent ways of doing that is: websockets, server-send events. Nice example of that is Firebase. You can find simple code example in: https://github.com/laithshadeed/wsk-feedback. In this example you will see that updating firebase will send event to the browser via websocket, then the UI will update.

This is called Comet/Reverse Ajax/HTTP server push http://en.wikipedia.org/wiki/Comet_(programming). They are many techniques for doing this as well as many existing frameworks to do it for you.

There are many answers in SO about Comet https://stackoverflow.com/search?q=comet

Simple implementation would be javascript setTimeout and setInterval to check server status, with trigger/stored procedure on mysql.

For depth dive into Comet. There are two cool books about this:

Comet and Reverse Ajax 2008 By Dave Crane

Chapter 4 (River of Content) – Building the Realtime User Experience 2010 By Ted Roden

Update: You may look to the newer techniques in HTML5 like Websockets and Server-sent Events, although IE does not support them well, at the moment Server-sent events is not supported in IE and Web Sockets only supported in IE10