[Dbix-class] Filtering a SELECT based on a calculation of two columns?

[Chris Cole]

On 17/02/11 15:19, Fahad Khan wrote:
>
> This might help:
>
> http://search.cpan.org/dist/DBIx-Class/lib/DBIx/Class/Manual/Cookbook.pod#Using_SQL_functions_on_the_left_hand_side_of_a_comparison
> http://search.cpan.org/~frew/SQL-Abstract-1.72/lib/SQL/Abstract.pm#Literal_SQL_with_placeholders_and_bind_values_%28subqueries%29
>

Thanks. I did find those pages before, but couldn't understand them :( 
With Rob Kinyon's reply I understand a bit more, but not much.