Lots of people are asking how to solve it with YII,We think its difficult with YII. But its easy to solve . There is no database triggers needed . we can simply sove it by extending a class(say "RActiveRecord") from CActiveRecord .Then extend all our model classes from that class.
Uploading files in a webapp can be extremely tricky and sometimes the quickest way to do it is to store the file directly in the webserver or into a DNS (like Amazon S3) and then to save the link and the metadata inside a table in the DB. The thing is that you'll have to deal with file permissions, server storage, file management and so on (which is perfectly fine, by the way).
The CGridView widget is very useful and customizable, but sometimes you need a little more.
One limit I found is to have only one row for headers; yes, you can write each column header in more than one row, but just inside the single cell.
I was looking instead for the possibility to use more than one row, with different structure one from the others.
This way you can write columns grouping headers, and obtain a nicer view.
Backoffice Grid Views often list information like Posts for a blog while showing at the same time linked information like the User who wrote that post.
For more efficiency, it is appropriate that the User is displayed as a link to the User detail page.
I assume you are familiar with accessControl standard filter. It allows you to separate privileges to run some action from action code itself. There is however one problem with most common usage - you cannot use bizRules, at least based on some parameters passed to 'checkAccess' just because it is hard to pass them in accessRules() result.