Ask A Question

Notifications

You’re not receiving notifications from this thread.

How do i add a ":unique => true" to an already existing reference?

Alan Reid asked in Rails

I have my DB already set up, and it references another table. I need to add in :unique => true so i don't get duplicates. I cant however drop the table and start over as there are items in the DB already.

I know i could do this if i wanted to add a column in to the DB, but what about when it already exists?

rails generate migration add_column_name_to_table_name column_name:references:uniq:index

Which would generate...

class AddIndexToModerators < ActiveRecord::Migration
  def change
    add_reference :table_names, :column_name, index: {:unique=>true}, foreign_key: true
  end
end
Reply

I think that you can use change_column method
change_column(table_name, column_name, type, options = {})
More info

Reply

add_reference :table_name, :column_name, unique: true, foreign_key: true

I think ;)

Reply
Join the discussion
Create an account Log in

Want to stay up-to-date with Ruby on Rails?

Join 81,149+ developers who get early access to new tutorials, screencasts, articles, and more.

    We care about the protection of your data. Read our Privacy Policy.

    Screencast tutorials to help you learn Ruby on Rails, Javascript, Hotwire, Turbo, Stimulus.js, PostgreSQL, MySQL, Ubuntu, and more.

    © 2024 GoRails, LLC. All rights reserved.