SQL or NoSQL for a web based chat application?

[Reard Gjoni]

I'm a Web Development Student and we are asked to do a project for Uni. I like the idea of making a chat application since it would be good practice for Ajax/REST. However, I am not sure about using an SQL or a NoSQL Database about this project.

What would be the differences for this project, pros and cons?!

Thank you in advance, Reard