Working with PHP & Flex requires more guidance than we can give here. I would check out their tutorials. wikidocs.adobe.com/wiki/display/Flex/Flex+and+PHP
It is not possible to connect directly to a database from flex. You can use some server side technology like Java Servlets/JSP or PHP to talk to the database, format the result and send that to your flex UI possibly as XML. Flex can then parse through that XML and display the data on the UI.
It is used to tell the sever to use the PHP parser. To begin php you must use <?php, and to end it, it is ?>.
You can't use PHP in an HTML document, but you can use HTML in PHP script.
They are designed for use in the tubular magazines (lever guns especially), but there is no reason you couldn't use them in any 30-30 even if they were box magazine fed, or even hand-load them for a .308, 30-06, etc. The purpose of the flex-tip is to keep them from firing the primer ahead of them in a tube.
PHP files extension is .php
Firstly, this is wrong question. The right one would be WHEN should you use PHP, not JSP? or, WHEN should you use PHP and WHEN JSP?
PHP 5 has a XML parser called SimpleXML that you could use.
You can use phpMailer() Or, you can use mail() PHP function to send emails via PHP script.
PHP certification is received after doing some sort of PHP course, there are many out there to do. You can use them in your CV to help you get a job in PHP.
Facebook uses PHP 5.
There are no PHP tags. Unlike HTML, PHP is not Markup language. They use scripts. An example would be <?php echo "Hello, World!"; ?>
That's PHP Engine.. Allow you to develop PHP Scripts.. you can use it to develop PHP Scripts and test it on your local machine before you send it to server.. (your website)