I want to make a form that adds you to a mailing list. I want to export the mailing list to a excel file. Does flex databases support this or is this something i would have to do with php/sql? I have seen many examples with php/sql but was wondering if its possible to do it all inside of flex?
Flex doesn't have databases, it communicates with them, the most common way is through php, when you say you want excel export is that a must as excel supports the xml format which is something that flex can handle very well.
The more 'normal' option would be is a server side mysql database that gets an email address added to it by the flex application(php insert function), flex could then call a php function to export the database email info to an excel spreadsheet.
 you can actually use php to read and write excel spreadsheets so you don't really need a database.