Question

I want to copy all the rows from my table with single column update.

Example.

Table County has 1000 rows and i want to copy all the rows with single column update.

What is the proper way to do that ?

Answer 1

This question describes how to use clone to copy your record.

Assuming the 1000 records are already in an Enumerable called counties, we end up with

counties.each { |county|  
    county_copy = county.clone
    county_copy.col3 = update_function(county_copy.col3)
    county_copy.save
}