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Hi Deborah,

>an you provide an example of when/how this new feature (addSelectExpr) would be used?
It's for pretty advanced MySQL. So likely it would be used by us or when we post a snippet to help someone in the forum.

What it does is insert the addSelectExpr value into a SELECT query here:
SELECT *, addSelectExpr FROM tablename

So if you had:
'addSelectExpr' => ' NOW() as _currentDate ',

It would add a field _currentDate to your $records like $records['_currentDate']. That's because NOW() is a mysql function: http://dev.mysql.com/doc/refman/5.1/en/date-and-time-functions.html#function_now

Usually you'd use that when you had lots and lots of records and you wanted to sort them on a calculated value. Some examples of this that I'm working on now are a custom search engine that returns records based on a "match score" from 0-100 that is calculated, and a distance search that returns results based on distance from the searching users location and displayed that distance as well.

Some of the MySQL for this can be very complicated (see: http://www.zcentric.com/blog/2007/03/calculate_distance_in_mysql_wi.html ) but as we do it more and more ourselves we'll work on ways to make it simpler and build it into the software or plugins.

If you have say 10,000 or more records you need to do these calculations and the sorting in the database because it's not possible to do it in the application without loading all the records and that takes too much memory.

The main reason I added it was because I needed it for a custom project I was working on myself.

Hope that helps! Let me know if you want any more details. :)