To be able to actually use database transactions you'd need them to extend across the form's lifetime. You can do that with a local application, but not with a webapp with the web request cycle.

> What about storing the results in memory until you can make sure it is successfully stored?

That has all the same problems as storing your data in memory and not using a datastore. In this scenario the data can never be stored because it now violates referential integrity.

> Also, what language/framework have you been using because these things are routinely handled by any that worth anything.

Many of the big-name Python or JVM-based ones, but it's a fundamental problem that can't be solved at that level. Which language/framework are you claiming handles this well?