Cách tốt nhất để nhóm theo ngày với Mongoid

Đây là câu trả lời sử dụng khung tổng hợp để nhóm theo ngày. Tôi hy vọng rằng bạn thích nó.

app / model / disease.rb

class Patient
  include Mongoid::Document
  field :name, type: String

  def self.group_by(field, format = 'day')
    key_op = [['year', '$year'], ['month', '$month'], ['day', '$dayOfMonth']]
    key_op = key_op.take(1 + key_op.find_index { |key, op| format == key })
    project_date_fields = Hash[*key_op.collect { |key, op| [key, {op => "$#{field}"}] }.flatten]
    group_id_fields = Hash[*key_op.collect { |key, op| [key, "$#{key}"] }.flatten]
    pipeline = [
        {"$project" => {"name" => 1, field => 1}.merge(project_date_fields)},
        {"$group" => {"_id" => group_id_fields, "count" => {"$sum" => 1}}},
        {"$sort" => {"count" => -1}}
    ]
    collection.aggregate(pipeline)
  end
end

test / unit / BN_test.rb

require 'test_helper'
require 'pp'

class PatientTest < ActiveSupport::TestCase
  def setup
    Patient.delete_all
  end

  test "group by date" do
    [
        {"name" => "John", "created_at" => Date.new(2012, 10, 10).mongoize},
        {"name" => "Jane", "created_at" => Date.new(2012, 10, 31).mongoize},
        {"name" => "Mary", "created_at" => Date.new(2012, 10, 31).mongoize},
        {"name" => "Mark", "created_at" => Date.new(2012, 12, 12).mongoize},
        {"name" => "Alex", "created_at" => Date.new(2013, 11, 10).mongoize},
        {"name" => "Andy", "created_at" => Date.new(2013, 10, 31).mongoize},
        {"name" => "Toni", "created_at" => Date.new(2013, 10, 31).mongoize},
        {"name" => "Cori", "created_at" => Date.new(2013, 11, 10).mongoize}
    ].each do |patient|
      Patient.create(patient)
    end
    puts "\nMongoid::VERSION:#{Mongoid::VERSION}\nMoped::VERSION:#{Moped::VERSION}"
    pp Patient.group_by('created_at', 'month')
  end
end

Kiểm tra $ rake

Run options:

# Running tests:

[1/1] PatientTest#test_group_by_date
Mongoid::VERSION:3.1.5
Moped::VERSION:1.5.1
[{"_id"=>{"year"=>2012, "month"=>10}, "count"=>3},
 {"_id"=>{"year"=>2013, "month"=>10}, "count"=>2},
 {"_id"=>{"year"=>2013, "month"=>11}, "count"=>2},
 {"_id"=>{"year"=>2012, "month"=>12}, "count"=>1}]
Finished tests in 0.042561s, 23.4957 tests/s, 0.0000 assertions/s.
1 tests, 0 assertions, 0 failures, 0 errors, 0 skips