Rails：活动记录地址数组中的唯一地址

Question

How to retrieve unique addresses which has got same latitude and longitude

> addresses
=> [#<Address id: 10, country: "IN", state: "KA", latitude: "12.971513803339702", longitude: "77.59443104418949", user_id: 11>, #<Address id: 9, country: "IN", state: "KA", latitude: "12.971513803339702", longitude: "77.59443104418949", user_id: 10>]

In this case I need any one of the ActiveRecord, as latitude and longitude are having similar values.

Answer 1

You could group the addresses by its latitude and longitude and then select the once with at least 2 addresses in a group:

addresses.
  group_by { |address| [address.latitude, address.longitude] }.
  select { |location, addresses| addresses.size >= 2 }.
  keys

Depending on your use case you might want to use distinct (note that you lose id and user_id information):

Address.select(:country, :state, :latitude, :longitude).distinct