Rails: “t.references” not working when creating index

Question

class CreateBallots < ActiveRecord::Migration
  def change
    create_table :ballots do |t|
      t.references :user
      t.references :score
      t.references          


        

Answer 1

You forgot to add "_id" like this:

add_index :ballots, :user_id

or, if you want it indexed automatically:

t.references :user, index: true

More info: add_index , references

HTH

Answer 2

The answer above is correct, but be aware that:

t.references :user, index: true is only available in Rails 4.0 & up.

In earlier versions of Rails (3.x), index: true will fail silently, leaving you without an index on that table. For Rails 3.2.x & down, use the older syntax:

add_index :ballots, :user_id

Or in full using your example:

class CreateBallots < ActiveRecord::Migration
  def change
    create_table :ballots do |t|
      t.references :user
      t.references :score
      t.references :election
      t.string :key
      t.timestamps
    end
    add_index :ballots, :user_id
    add_index :ballots, :score_id
    add_index :ballots, :election_id
  end
end