Can I set a Model attribute to array in Rails?

Julia
1 min readDec 13, 2020

Recently I was coding something in Ruby on Rails and I came to a question if I can have array as an attribute for my Model. I started look for Rails documentation and found all available datatypes for Active Records migration

:binary ,:boolean, :date, :datetime, :decimal,:float, :integer, :bigint, :primary_key, :references, :string, :text, :time, :timestamp

I also found that you might use a type that is not in this list as long as it is supported in your database. Database that I primary work with is PostgreSQL. It supports many others data types, like:array and :hstore (which is a hash). So yes, we can store multiple values (arrays or hashes) in one column.

Here is how the migration file should look like in order to get attribute as array:

class CreateStore < ActiveRecord::Migration
def change
create_table :stores do |t|
t.string :name
t.string :address, array: true, default: []

t.timestamps
end
end
end

If you want the default value to be an empty array set the default to [], otherwise, the attribute is nil, until you give it a value.

rails c 
> Store.first
> #<Store id: 1, name: "SmartCost", address: ["Location 1", "Location 2"] >

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