I've got an interesting problem. I'm dealing with a legacy database,
and for one of my models I always want to ignore records that have a
particular column set. I would like to pretend like they don't exist.
When I run MyModel.find() I don't want them to show in the result set.
I considered using after_find() to do this, but that gets called on
every item in the found collection, not the entire collection. Is there
some easy way to modify MyModel to insert a :conditions statement (or
modify a pre-existing one) on all queries issued by the model? Ideally
it would be transparent enough that the other models don't need to know
anything about it.