Ruby on rails 错误数据库：迁移

将数据库从应用程序迁移到新服务器后，当我运行命令RAILS_ENV=production rake db:migrate时，出现以下错误：

==  AggregatedGlobalRolesMigrations: migrating ================================
-- add_column(:roles, :type, :string, {:limit=>30, :default=>"Role"})
rake aborted!
StandardError: An error has occurred, all later migrations canceled:

Mysql2::Error: Duplicate column name 'type': ALTER TABLE `roles` ADD `type` varchar(30) DEFAULT 'Role'/home/openproject/.rvm/gems/ruby-2.1.4/gems/activerecord-3.2.21/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:245:in `query'
/home/openproject/.rvm/gems/ruby-2.1.4/gems/activerecord-3.2.21/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:245:in `block in execute'
/home/openproject/.rvm/gems/ruby-2.1.4/gems/activerecord-3.2.21/lib/active_record/connection_adapters/abstract_adapter.rb:280:in `block in log'
/home/openproject/.rvm/gems/ruby-2.1.4/gems/activesupport-3.2.21/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
/home/openproject/.rvm/gems/ruby-2.1.4/gems/activerecord-3.2.21/lib/active_record/connection_adapters/abstract_adapter.rb:275:in `log'
/home/openproject/.rvm/gems/ruby-2.1.4/gems/activerecord-3.2.21/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:245:in `execute'
/home/openproject/.rvm/gems/ruby-2.1.4/gems/activerecord-3.2.21/lib/active_record/connection_adapters/mysql2_adapter.rb:213:in `execute'
/home/openproject/.rvm/gems/ruby-2.1.4/gems/activerecord-3.2.21/lib/active_record/connection_adapters/abstract_mysql_adapter.rb:461:in `add_column' ..........

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有没有人遇到过类似的问题并能提供帮助？

显然，您已经有了列类型

类型在ActiveRecord中用于STI。。。您可以尝试使用不同的列名，例如type of，并查看是否排序。

Mysql2:：错误：重复列名“type”：ALTER TABLE roles ADD type varchar30 DEFAULT，这意味着该类型列已存在于表中