method

up_only

v6.1.3.1 - Show latest stable - 0 notes - Class: ActiveRecord::Migration

1.0.0
1.1.6
1.2.6
2.0.3
2.1.0
2.2.1
2.3.8
3.0.0
3.0.9
3.1.0
3.2.1
3.2.8
3.2.13
4.0.2
4.1.8
4.2.1
4.2.7
4.2.9
5.0.0.1
5.1.7
5.2.3 (0)
6.0.0 (0)
6.1.3.1 (0)
6.1.7.7 (0)
7.0.0 (0)
7.1.3.2 (0)
7.1.3.4 (0)
What's this?

up_only() public

Used to specify an operation that is only run when migrating up (for example, populating a new column with its initial values).

In the following example, the new column published will be given the value true for all existing records.

class AddPublishedToPosts < ActiveRecord::Migration[6.0]
  def change
    add_column :posts, :published, :boolean, default: false
    up_only do
      execute "update posts set published = 'true'"
    end
  end
end

Show source

# File activerecord/lib/active_record/migration.rb, line 805
    def up_only
      execute_block { yield } unless reverting?
    end

up_only

Related methods