Active Record 4 now has support for PG's Array data-type. Here's how you might use it to give users multiple email addresses: Migration: class AddEmailsToUser < ActiveRecord::Migration def change add_column :users, :emails, :string, array: true, default: '{}' end end Notice: * it's specified as data type :string with array: true * to default the column to an empty array ( [] ), you use default: '{
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