Database backup

Hello, I developed a RoR application where users can create personal accounts with several informations. Those informations are divided in various tables of the database. The thing is I want to create a function so that they can backup all the information corresponding to their account. The idea is to add a button in their profile page let's say "backup my account" that would trigger the function, create the database file with their data and download the file so that if anything occurs on the database they would be able to upload the file and get their account back without any problem.

I've been looking on the internet and found a few things, for example the "rake db:backup:write" (that is giving me a "no such file to load -- spec" actualy). But the thing is I don't want to save all the database but only the part that correspond to the account of the user that is using the function. I could create a function that would get all the account information and generate an sql or csv file by my own but I though maybe something already exists.

Any idea?

Olivier.