Developing Rich Internet Applications that access databases always require a complex infrastructure in the background. The same applies to Flex.
Really?
What if data can be sent to the server in form of SQL queries without compromising security? This would certainly come with many benefits but also challenges and risks:

Benefits:

• Server backend can be static and does not have to be modified for new applications
• Developers can focus entirely on the frontend/GUI which saves a tremendous amount of time
• New database applications can be created in hours or a few days even by novices
• No complex infrastructure required

Challenges/Risks:

• Server has to do session management so that users have to be logged in and authorized to be able to send SQL queries and receive its results
• Server has to filter queries that delete tables or databases
• Server has to filter queries to prevent SQL injection attacks (which certainly applies to other applications as well)
• Access rights to enable/disable sections of an application are handled on the client
• Access rights to permit access to data records is handled by the database

I would conclude that if the risks are being closely evaluated and appropriate steps are initially taken to implement solutions it is possible to create Flex (and other RIA) applications without any backend development for new projects at all.

At Comparatio we developed an Open Source framework that solves this task. The framework can access many different databases - even at the same time within the same application.
Everything is based on templates so that lists and forms look and work consistently across the entire application.
You can download the system and check out demos at www.comparatio.com . Any feedback is greatly appreciated!

Read more from Jan Poehland.