Change Column Name Migration - Part2

In the article Change-Column-Name-Migration-Part1 I talked about creating two migrations to rename a column name of a model.

However, by studying and coding more, I learned that creating only one migration which renames it is possible. Which looks like this:

rails g migration change_column_name

And generated the following ruby file:

class ChangeColumnName < ActiveRecord::Migration
 def change
 end
end

I had to include this line with the table name, old column name, and new column name that I wanted to rename it for. So, in the end my migration looked like this:

class ChangeColumnName < ActiveRecord::Migration
 def change
  rename_column :warehouses, :codi, :code
 end
end

OBS.: If needed to change more than one column name you could repeat this line, like this:

rename_column :table_name, :old_column1, :new_column1
rename_column :table_name, :old_column2, :new_column2
...

But, in this case, is best to use change_table that would look like this:

class ChangeColumnsNames < ActiveRecord::Migration
 def change
    change_table :table_name do |t|
      t.rename :old_column1, :new_column1
      t.rename :old_column2, :new_column2
      ...
    end
  end
end

OBS.: Change_table can be used to make different changes in one table, like rename, change column type, remove… Example