You're probably better using the built-in SQLite database.
If you want to use MySql here are some links:
If this post answers your question or helps, please mark it as such.
Greg Lafrance - Flex 2 and 3 ACE certified
Flex / AIR Development, Training, and Support Services
A first thanks for your answer.
I note that you talk about sqlitelite, but in my case I'm affraid that sqllite is not enough perform wheb 20 user try to access to the database.
With you solution, i need to find how to install easily, in my customer office, apache and php.
Do know a solution to do that?
A other question is about php request, indeed i read a lot about that but i didnt find how to create this file with AS3.
If they're on a Mac, PHP and Apache are installed by default and MySQL is an installer away.
Alternatively, try googling "MAMP" or "WAMP" which I believe is an all-in-one virtual box solution for Mac and Windows respectively.
What you need to do to get AIR and MySQL working together is an HTTP server like Apache and a programming language to make the link between the two. (PHP, Java etc).
I use PHP. In adition to Apache, MySQL and PHP you will also need a PHP library for AMF. (e.g. AMFPHP, WebORB, ZendAMF etc).