Performing MySQL queries with the help of AJAX

Back to AJAX! This tutorial is a reply to a question posted in Experts Exchange, and therefore it has a very specific scope. However, taking into consideration it may prove to be useful to many, I decide to share it with you all.

What this tutorial explains is how to perform asynchronously MySQL actions with AJAX, using GET variables and an external PHP page. It may sound super-complex, but it is not. As usual, I provide the full code of the script and a working demo which you can see here.

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Saving multiple selections from drop down list to database

This post will teach you how to process and store multiple selections from a form element into a MySQL database, using PHP. In order to understand how it works, you will need basic knowledge of PHP arrays, because they’re necessary for achieving the results.

If you still don’t know what arrays are and how do they work, read Tizag’s array tutorial first.

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Checking availability of user name with AJAX

Lately I’ve been writing quite much about AJAX, but it is so useful that I’m sure it is of everyone’s interest!

In this post I will show you – as the post title says – an example script of AJAXed registration form, without recurring to AJAX frameworks (there are already many tutorials about this topic in relation with them). The example omits the synchronous part of the registration and focuses on the user name, which we want to asynchronously check. It doesn’t sound so weird if I say it in other words: check on the fly if the user name the person is typing already exists in the database or not, and take actions depending on whether it does or not (for instance, only allow form submission if name is available).

This is the basis for other types of effects like for instance searching contents and dynamically returning result suggestions, or checking if a specific word exists in the database, etc. but as I mentioned, here the intention is to use it on a registration form.

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