Rails 4: Remove not null constraint from table column with migration?

Given the following schema.rb:

  create_table "people", force: true do |t|
    t.string   "name",  null: false
    t.integer  "age"
    t.integer  "height"
    t.string   "email"
    t.boolean  "married",  default: false
    t.text     "bio"
    t.integer  "fav_number"
    t.decimal  "lucky_num",  precision: 2, scale: 2
    t.datetime "birthday"
    t.datetime "created_at"
    t.datetime "updated_at"
  end

I'd like to remove the name default value of null: false. I've tried running a separate migration with change_column_default, but that had no impact on schema.rb. Any suggestions?

Solution 1:

From the docs:

  def up
    change_column_default :table_name, :status, 0
  end

  def down
    change_column_default :table_name, :status, nil
  end

Solution 2:

The 'up' function will definitely do the job when you do db:migrate.
But in the future, in some cases, like rollback, you might want a function to reverse this particular migration.

def up
  change_column_null :people, :name, true
end

def down
  change_column_null :people, :name, false
end

Solution 3:

It sounds like you're not trying to change the default value of the column, but rather to remove the NOT NULL constraint and allow null values (i.e. change from "null: false" to the default "null: true"). If that's the case, then you can use change_column_null:

class ChangeNameNull < ActiveRecord::Migration
  def change
    change_column_null :people, :name, true
  end
end

Edit 1:- Fixed typo