ruby-on-rails - 如何做 rails db :migrate on multiple shards that are not master slave relationship at once on rails?

Question

我有一个应用程序，它根据子域使用不同的数据库。所以本质上，模式是相同的，但每个数据库的数据会有所不同。但是当我发布一些新功能并且需要一些架构更改时，我需要运行一个命令，该命令将在 shards.yml 中配置的所有数据库上运行。 .

数据库.yml

default: &default
  adapter: postgresql
  encoding: unicode
  pool: 15
  host: localhost
  port: 5432
  username: postgres
  password:

development:
  <<: *default
  database: app_default
production:
  <<: *default
  database: app_default
  username: <%= ENV['BACKEND_DATABASE_USERNAME'] %>
  password: <%= ENV['BACKEND_DATABASE_PASSWORD'] %>

shards.yml

shared: &shared
  adapter: postgresql
  encoding: unicode
  pool: 15
  host: localhost
  username: postgres
  password: 
  port: 5432

octopus:
  environments:
    - development
    - test
    - production
  development:
    default:
      <<: *shared
      database: app
    first:
      <<: *shared
      database: first
    second:
      <<: *shared
      database: second
    ....
  test:
    test:
      host: postgres
      adapter: postgresql
      database: app_test
  production:
    default:
      <<: *shared
      database: app
    first:
      <<: *shared
      database: first
    second:
      <<: *shared
      database: second
    ....

我正在使用 Octopus 基于子域设置分片，效果很好。我遇到的问题是:

我做不到 rails db:reset .收到错误 ActiveRecord::StatementInvalid: PG::ObjectInUse: ERROR: cannot drop the currently open database

我做不到 rails db:migrate将迁移到所有数据库

Answer 1

您必须添加 using到您的迁移

class CreateComments < ActiveRecord::Migration
  using :first, :second

  def change
    create_table :comments do |t|
      t.belongs_to :page, index: true
      t.text :body

      t.timestamps
    end
  end
end

上述迁移将在 first 上运行和 second