sorting

Hello,

I'm trying to figure out the best way to use the Views (v1.x) API to create a custom sort function for a CCK type.

Here's what I have:

CCK fields:

• title (string)
• rating_a (int)
• rating_b (int)
• rating_c (int)
• rating_d (int)

I need to develop a way to sort the view by the average of a variable number of the "rating" CCK fields.

For example, if the user wants to sort the nodes only by "rating_a" and "rating_c", then the "order by" clause would look something like this: