Modify column expressions being selected in SQL query

Hi all,

What is the most ‘orthodox’ and correct way of altering expressions, which are put into the select statement by default by CActiveDataProvider? For example, I need:

[sql]select some_function(col1), some_other_function(col2)

from my_table[/sql]

Or do I have to quit using ActiveRecord for that and use Yii DAO directly instead?

Do you mean something like CDbExpression?

Maybe. Could you point out an example on how it can be used for the above task?