CButtonColumn in CGridView can be customised to include user built buttons. To learn a great deal about including custom buttons, read this excellent wiki.
This tutorial will show how to call an action from one custom button using AJAX instead of regular GET calls.
In many cases developers of one project use their own local environments for coding. There may be a common test platform and, of course, production. All these environments usually have different DB credentials and directory structures (first of all, path to YII framework directory). Another feature is debugging. It's convenient to turn it on for local environments, eventually - on the test server and never (generally speaking) - on the production.