Adding same column name to different tables - Rails Migration

Question

I just want to make sure if this is possible:

class AddUpdatedById < ActiveRecord::Migration
  def change
    add_column :clients, :updated_by_id, :integer
    add_column :contacts, :updated_by_id, :integer
    add_column :court_agencies, :updated_by_id, :integer
  end
end

This way I will save migrations. Because if I will migrate them one by one, I think it will take more time and mess up my migrations. So, what do you think?

Is it possible or I should I do the same thing one by one?

Answer 1

Yes, you can do this, but normally u wanna keep the related changes in same migration file

Answer 2

Yes, you can. Migrations can contain virtually an unlimited list of commands. For example, if you query on those IDs, you should also add an index on the id.

The idea is to group in the same migration only a set of operations that reference the same concept, like in this case.

If you have several changes, such as a creation of a model table, a new field and an index, and these changes are not part of the same feature or batch of operations, than simply create multiple files.

In this case, the goal is to add the UpdateById field. It makes sense to use a single migration.

Answer 3

Yes you can, it will be a group migration.you can also do something like this to write less code if you want to change many tables.

def change
  tables = [:clients, :contacts, :court_agencies]

  tables.each do |table_name|
    add_column table_name, :updated_by_id, :integer
  end
end

if you decided to rollback this migration it will remove the columns without any problems.