Hier ist eine Antwort, die das Aggregationsframework verwendet, um nach Datum zu gruppieren. Ich hoffe, dass es dir gefällt.
app/model/patient.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/patient_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
$ Rake-Test
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
