How to get a single column’s values into an array

In Rails 3.2 there is a pluck method for this

Just like this:

Person.pluck(:id) # SELECT people.id FROM people
Person.pluck(:role).uniq # unique roles from array of people
Person.distinct.pluck(:role) # SELECT DISTINCT role FROM people SQL
Person.where(:confirmed => true).limit(5).pluck(:id)

Difference between uniq and distinct