Question

我需要一些帮助，通过'ruby中的查询来排序mongo'组。

我让小组按部分工作。下面的查询按小时对记录进行分组，返回的结果如下：

{"date"=>"2013,4,2,18,0,0,0", "count"=>1.0}
{"date"=>"2013,4,9,19,0,0,0", "count"=>1.0}
{"date"=>"2013,3,13,2,0,0,0", "count"=>3.0}

理想情况下，结果将按“日期”字段排序。

data = db[collection_name].group(
"function(doc) {
var dateKey = doc.created_at.getFullYear() + ',' +
(doc.created_at.getMonth() + 1) + ',' + doc.created_at.getDate() + ',' +
doc.created_at.getHours() + ',0,0,0';
return {'date': dateKey};}", 
{"parent_id" => parent_id, "checked" => true},
{ :count => 0 },
"function(doc, y){y.count++}",
true)

Answer 1

Ruby有一个内置的sort_by函数用于enumberables（包括数组）。

array = [
  {"date"=>"2013,4,2,18,0,0,0", "count"=>1.0},
  {"date"=>"2013,4,9,19,0,0,0", "count"=>1.0},
  {"date"=>"2013,3,13,2,0,0,0", "count"=>3.0}
]

p array.sort_by { |item| item['date'] }

# => [
#  {"date"=>"2013,3,13,2,0,0,0", "count"=>3.0}, 
#  {"date"=>"2013,4,2,18,0,0,0", "count"=>1.0}, 
#  {"date"=>"2013,4,9,19,0,0,0", "count"=>1.0}
#]

编辑：您还可以将时间解析为块中的Time对象，以确保正确排序。

require 'time'

array = [
  {"date"=>"2013,4,2,18,0,0,0", "count"=>1.0},
  {"date"=>"2013,4,9,19,0,0,0", "count"=>1.0},
  {"date"=>"2013,3,13,2,0,0,0", "count"=>3.0},
  {"date"=>"2013,4,13,2,0,0,0", "count"=>2.0}
]

p array.sort_by { |item| Time.parse(item['date']) }

# => [
#   {"date"=>"2013,3,13,2,0,0,0", "count"=>3.0}, 
#   {"date"=>"2013,4,2,18,0,0,0", "count"=>1.0}, 
#   {"date"=>"2013,4,9,19,0,0,0", "count"=>1.0}, 
#   {"date"=>"2013,4,13,2,0,0,0", "count"=>2.0}
# ]

在Ruby中通过查询对mongo组进行排序

1 个答案: