我正在使用carrierwave gem(版本0.8.0)。当我制作“rake db:migrate”时,我看到了奇怪的错误:
== AddAttachmentLogoToMerchants: migrating ===================================
-- change_table(:merchants)
rake aborted!
An error has occurred, this and all later migrations canceled:
undefined method `attachment' for ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::Table:0x007f900e6bde88
我的迁移:
def self.up
change_table :merchants do |t|
t.attachment :logo
end
remove_column :merchants, :logo_filename
end
def self.down
add_column :merchants, :logo_filename, :string
drop_attached_file :merchants, :logo
end
我该如何解决?