CakePHP, Codeigniter, and Laravel are all PHP frameworks, so not sure what you mean by "downgrade" your knowledge of mySQL and PHP. These frameworks simply make

CakePHP, Codeigniter, and Laravel are all PHP frameworks, so not sure what you mean by "downgrade" your knowledge of mySQL and PHP. These frameworks simply make it easier to build applications using PHP and to interact with mySQL (along with other databases) using a MVC convention. If you understand the concepts behind MVC really the only challenge is mapping functionality between the frameworks. While initially it may be confusing to figure out that mapping as each framework does not have the same function names or implement a concept the same way, once you get the general idea of using the new framework it will seem much easier. My recommendation is to find and work through a couple sample applications in CakePHP. Get an understanding of the functions and how they are used before trying to dig into the actual code of the site. I would avoid converting entirely to a new framework though if you don't have to.