Enum attributes are great and I want to use them. But mapping enum values to integer would make it hard to maintain both code and database. Also my database would be highly coupled with my code which I think I should consider that a bad thing.
I know I can use a hash to organize an enum attribute with key/value pairs, but still it would be a lot better to be able to use an array and map to string values in database.
Is there any way to map enum to strings by default?
As far as I know it's not possible with Active Record's built-in enum functionality. However, there are a few popular 3rd party gems that do this. The closest match to what comes with Active Record are probably enumerize and SimpleEnum.
However, if you're looking for something a little different, I'd recommend ClassyEnum (full disclosure: I wrote it). Here are some of my notes on the difference between enumerize and SimpleEnum vs ClassyEnum:
Class-less enums (enumerize, SimpleEnum) are great for simple use cases where you just need a field to represent one of a fixed set of values. The main issue I have with this solution is that it encourages conditionals scattered throughout your models, controllers and views. It's tempting to use these gems because they are the simplest to implement, but the long term payoff just isn't there IMO for anything but the simplest cases.
ClassyEnum was designed to solve the problem of having scattered conditional logic related to the different enums. You can still use it for simple collections that don't have logic, but when you do need to add logic (and you almost certainly will), you can push that into the individual enum classes and take advantage of polymorphism.