ruby-on-rails – MongoDB与Mongoid在Rails – 地理空间索引

class Item
  include Mongoid::Document

  field :loc,:type => Array

  index(
      [
          [:loc,Mongo::GEO2D]             
      ],background: true

  )
end

和查询

$near命令(不带maxDistance)

location = [80.24958300000003,13.060422]
 items = Item.where(:loc => {"$near" => location})

$near命令(带maxDistance)

distance = 10 #km
 location = [80.24958300000003,13.060422]
 items = Item.where(:loc => {"$near" => location,'$maxDistance' => distance.fdiv(111.12)})

使用km时转换距离为111.12(一度约为111.12公里),或者使用距离离开距离

$centerSphere / $nearSphere查询

location = [80.24958300000003,13.060422]
items = Item.where(:loc => {"$within" => {"$centerSphere" => [location,(distance.fdiv(6371) )]}})

这将找到10公里半径内的物品.在这里,我们需要转换距离/ 6371(地球半径)以使其与km一起工作.

$box(边框查询)

first_loc = [80.24958300000003,13.060422]
 second_loc = [81.24958300000003,12.060422]
 items = Item.where(:loc => {"$within" => {"$box" => [first_loc,second_loc]}})

这将帮助您找到给定边框内的项目.