batch insert by Mongoid (from http://stackoverflow.com/questions/3772378/batch-insert-update-using-mongoid)

mongoid_batch_insert.rb

batch = [{:name => "mongodb"}, {:name => "mongoid"}]  
Article.collection.insert(batch)

# my example
batch = [{ :name =>  '最高权限管理员', :level => DbRole::SuperAdmin }, { :name =>  '内容管理员', :level => DbRole::ContentAdmin }, { :name => '普通用户', :level => DbRole::NormalUser }]
DbRole.collection.insert(batch)