how to ad a "virtual column" to a model

Remco Hh wrote:

is it possible to define a column in a model, which is not present in the table? this column should return a combination of two other columns.

Model.columnC=Model.columnA+"-"+Model.columnB

A and B are in the table, C isn't

If you just want to grab this value, you just need a standard Ruby method in your model definition:

def columnC   columnA + "-" + columnB end

If you want to be able to write to this attribute as well, then you'll have to write a method along the lines of

def columnC=(new_value)   columnA, columnB = new_value.split("-")   new_value end

although obviously there is some ambiguity with "strings-like-this".

Hope that helps, Chris