我遷移現有的Rails應用程序使用MongoDB的(與Mongoid),和我有一些麻煩搞清楚如何做聚合一樣可以與MySQL做。用的MongoDB/Mongoid集合函數和計算領域
以前我有這樣的事情SELECT DATE(created_at) AS day, SUM(amount) AS amount GROUP BY day
,這將返回一個集合,您可以通過在模板中像這樣的循環:
:day => '2011-03-01', :amount => 55.00
:day => '2011-03-02', :amount => 45.00
etc...
有誰知道怎麼做,在Mongoid?該模型非常簡單:
class Conversion
include Mongoid::Document
include Mongoid::Timestamps
field :amount, :type => Float, :default => 0.0
...
# created_at generated automatically, standard Rails...
end
謝謝!
-Avishai
實際工作!更痛了一下,比標準的ActiveRecord樣式的查詢使用,因爲你要得到的結果爲'結果[「_ ID」] [「值」] [「量」]',但很酷:-) – Avishai 2011-03-27 12:45:47