Assume, we have a model, let's call it Articles. There, we have two columns, **min** and **max**. The rule is: **min** can't be greater or equal to **max**. How do you resolve this custom type of validation? Any ideas?

Going further, let's assume that we have columns **character** and **made\_of**. Task is to create a validation which is gonna help to avoid a situation, when "character = human" and "made\_of = steel".

Is there are standard routines to manage "metaphysical" conflicts between columns?