Rails迁移语法错误

Question

当我尝试一个rake db:migrate时，我看到了这个错误

/db/migrate/20180124161533_a_dd_uid_to_appuser_and_response.rb:22: syntax error, unexpected '\n', expecting =>

但是，根据我所看到的，在迁移文件中没有看到任何新行：

class ADdUidToAppuserAndResponse < ActiveRecord::Migration

  disable_ddl_transaction!

  def change

    add_column :appusers, :archived, :boolean, algorithm: :concurrently, if !column_exists?(:appusers, :archived)
    add_column :responses, :archived, :boolean, algorithm: :concurrently, if !column_exists?(:responses, :archived)
    add_column :appuser_rewards, :archived, :boolean, algorithm: :concurrently, if !column_exists?(:appuser_rewards, :archived)

    add_column :appusers, :last_checked_campaigns_at, :datetime, algorithm: :concurrently, if !column_exists?(:appusers, :last_checked_campaigns_at)
    add_column :appusers, :last_checked_for_available_campaigns_at, :datetime, algorithm: :concurrently, if !column_exists?(:appusers, :last_checked_for_available_campaigns_at)    

    add_column :appusers, :uid, :uuid, default: 'uuid_generate_v4()', algorithm: :concurrently, if !column_exists?(:appusers, :uid)
    add_column :responses, :uid, :uuid, default: 'uuid_generate_v4()', algorithm: :concurrently, if !column_exists?(:responses, :uid)
    add_column :appuser_rewards, :uuid, :uuid, default: 'uuid_generate_v4()', algorithm: :concurrently, if !column_exists?(:appusers, :uuid)

    add_index :appusers, :uid, algorithm: :concurrently, where: "archived = false", if !index_exists?(:appusers, :uid)
    add_index :responses, :uid, algorithm: :concurrently, where: "archived = false", if !index_exists?(:responses, :uid)


  end
end

知道问题出在哪里吗？

Answer 1

下面是如何修改代码的示例。只需删除所有行的,语句之前的if语句即可。例如，行：

add_column :appusers, :archived, :boolean, algorithm: :concurrently, if !column_exists?(:appusers, :archived)

应该是：

add_column :appusers, :archived, :boolean, algorithm: :concurrently if !column_exists?(:appusers, :archived)