将SQL转换为Datamapper请求

Question

是否可以将此SQL查询请求转换为Datamapper？

SELECT twitchtv 
FROM twitchtvsts 
WHERE twitchtvsts.user_id = thisisavaraible


get '/watch/:id' do |id|
    erb :mystream 
    result = repository(:default).adapter
                             .select(
                                     'SELECT twitchtv 
                                      FROM twitchtvsts 
                                      WHERE twitchtvsts.user_id = id'
                                    )
    puts result

Answer 1

写如下：

Twitchtvsts.all( :fields => [:twitchtv ], 
                 :conditions => { :user_id => id_var }           
               )

阅读此Projecting only specific properties。