Relational databases do not support inheritance so if we need to represent it, we have to somehow store meta info while keeping performance by minimizing JOINs. One way to solve this problem is using single table inheritance. All fields for the whole class tree are stored in a single table. Class name is stored in the type field of the same table.
Sometimes it would be nice if we could run yiic from an action, for example a migrate database button in our admin panel.
Or because you are on a host which doesn't have shell access.
Or maybe you are not allowed run popen or exec.
Something a good application cant miss is documentation, and what would be better than some nice formatted HTML documentation that can be auto-generated from your code, we know several tools that already do this like phpDocumentor, but today we are introducing Yii Docs Generator which is a modification of the code that Yii itself uses to generate its documentation, thank phpnode for this wonderful work.
Yii makes it really easy for all to use their already made objects that automate everything we do. It provides also great power of flexibility and styling but hey, we programmers tend to complicate our lives and push a little more the power of our tools.