gitlab-org--gitlab-foss/db/migrate/20180305095250_create_internal_ids_table.rb

class CreateInternalIdsTable < ActiveRecord::Migration[4.2]
  include Gitlab::Database::MigrationHelpers

  DOWNTIME = false

  def change
    create_table :internal_ids, id: :bigserial do |t|
      t.references :project, null: false, foreign_key: { on_delete: :cascade }
      t.integer :usage, null: false
      t.integer :last_value, null: false

      t.index [:usage, :project_id], unique: true
    end
  end
end
Add version 4.2 to all existing migrations DB schema generated by a migration may look different in rails 4 and 5 (because rails 5 may use different default values). For this reason it's important to explicitly set for which rails version a migration was written for. See https://stackoverflow.com/questions/35929869/activerecordmigration-deprecation-warning-asks-for-rails-version-but-im-no/35930912#35930912 2018-11-13 02:27:31 -05:00			`class CreateInternalIdsTable < ActiveRecord::Migration[4.2]`
Atomic generation of internal ids for issues. 2018-03-06 14:09:01 -05:00			`include Gitlab::Database::MigrationHelpers`

			`DOWNTIME = false`

Address review comments. 2018-03-16 08:34:08 -04:00			`def change`
Use bigserial for internal_ids table. 2018-03-12 13:12:38 -04:00			`create_table :internal_ids, id: :bigserial do \|t\|`
Simplify migration and add NOT NULL to project_id. 2018-03-14 08:42:24 -04:00			`t.references :project, null: false, foreign_key: { on_delete: :cascade }`
Atomic generation of internal ids for issues. 2018-03-06 14:09:01 -05:00			`t.integer :usage, null: false`
			`t.integer :last_value, null: false`

Simplify migration and add NOT NULL to project_id. 2018-03-14 08:42:24 -04:00			`t.index [:usage, :project_id], unique: true`
Atomic generation of internal ids for issues. 2018-03-06 14:09:01 -05:00			`end`
			`end`
			`end`