使用 rake db：直接迁移、普通 SQL

发布于 2024-10-16 11:49:12 字数 444 浏览 2 评论 0原文

使用 rake db:migrate 加载普通 SQL 会涉及哪些问题？

我正在处理的业务需求不允许我使用默认的 Rails 迁移。但我仍然需要跟踪更改、轻松更改数据库 DDL 以及 Rails 迁移为您提供的其他功能。

所以迁移文件看起来像：

class AddDateToPost < ActiveRecord::Migration
  def self.up
    ActiveRecord::Base.connection.execute("ALTER TABLE `posts` ADD COLUMN date DATETIME NULL")
  end

  def self.down
    ActiveRecord::Base.connection.execute("ALTER TABLE `posts` DROP COLUMN date")
  end
end

原文

What gotchas would be involved by using rake db:migrate to load vanilla SQL?

The business requirements that I am working with don't allow me to use the default Rails' migrations. But I still need to track changes, easily alter the database DDL, and the other things that Rails' migrations give you.

So a migration file would look like:

class AddDateToPost < ActiveRecord::Migration
  def self.up
    ActiveRecord::Base.connection.execute("ALTER TABLE `posts` ADD COLUMN date DATETIME NULL")
  end

  def self.down
    ActiveRecord::Base.connection.execute("ALTER TABLE `posts` DROP COLUMN date")
  end
end

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逆光下的微笑 2024-10-23 11:49:12

这是完全可以接受的，并且没有任何问题，只要您确信您的 up 和 down 函数相互镜像即可。为了便于阅读，我建议执行以下操作：

class AddDateToPost < ActiveRecord::Migration
  def self.up
    execute "ALTER TABLE `posts` ADD COLUMN date DATETIME NULL"
  end

  def self.down
    execute "ALTER TABLE `posts` DROP COLUMN date"
  end
end

That's perfectly acceptable and there are no gotchas, as long as you feel confident that your up and down functions mirror each other. I would suggest doing the following for readability:

class AddDateToPost < ActiveRecord::Migration
  def self.up
    execute "ALTER TABLE `posts` ADD COLUMN date DATETIME NULL"
  end

  def self.down
    execute "ALTER TABLE `posts` DROP COLUMN date"
  end
end

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拥抱影子 2024-10-23 11:49:12

您可以通过使用 standalone-migrations 宝石。

安装 gem 后，将以下行添加到您的 Rakefile 中以启用 rake db:* 任务：

require 'standalone_migrations'
StandaloneMigrations::Tasks.load_tasks

之后，您只需像平常一样设置迁移：

class AddDateToPost < ActiveRecord::Migration
  def self.up
    add_columm :posts, :date, :datetime, default: nil
  end

  def self.down
    remove_columm :posts, :date
  end
end

You can use the Rails migration methods in a non-rails project by using the standalone-migrations gem.

After installing the gem you add the following lines to your Rakefile to enable rake db:* tasks:

require 'standalone_migrations'
StandaloneMigrations::Tasks.load_tasks

After that you simply setup your migrations as you would normally do:

class AddDateToPost < ActiveRecord::Migration
  def self.up
    add_columm :posts, :date, :datetime, default: nil
  end

  def self.down
    remove_columm :posts, :date
  end
end

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