When would you want to use arrays?
A common scenario for arrays is when you have tags for an article or a recipe. Each article can have one or more tags and you usually need to create a new “tags” table for it (or you serialize it). Allowing you to have a native tags column saves you from adding additional complexity you might not want. No new table, no model, no indexes…. just a new column that you can save your tag array straight to it.
How to use it?
Migrations now support it by using t.array and passing array_type
t.array :tags, array_type: :string t.array :votes, array_type: :integer t.array :bool_arr, array_type: :boolean
Creating an object is as simply as
Post.create!(title: 'Arrays are awesome', tags: %w(hot fresh), votes: [1,2])
… and querying for it
post = Post.where("'hot' = ANY (tags)")