Rank Query Results - Rails - sql

Question

I've got the following query that searches my customer database and does so successfully:
SELECT "customers".* FROM "customers" WHERE ((("customers"."first_name" IN ('John', 'Doe') OR "customers"."last_name" IN ('John', 'Doe')) OR "customers"."email" IN ('John', 'Doe')) OR "customers"."main_phone" IN ('John', 'Doe'))
The equivalent Rails query is:
array = ["John","Doe","111-111-1111"]
Customer.where(first_name: array).or(customers.where(last_name: array)).or(customers.where(email: array)).or(customers.where(main_phone: array))
This works fine, however I am wanting to rank the results. For example, if record # 1 matches for both first and last name, I want that record to display at the top of my results. How could I do this?

Answer 1

The combination of where and or actually create a single SQL query with no "precedence" of the results
You will have to
1. break it down to separate queries
2. for each record found, count in how many queries it was found
3. order your results by this counter in descending order
Here is some code (it can be prettier):
class Customer < ApplicationRecord
def self.relevance_search(query)
matches = []
matches << Customer.where(first_name: query)
matches << Customer.where(last_name: query)
matches << Customer.where(email: query)
matches << Customer.where(main_phone: query)
counter = {}
matches.each do |match|
match.each do |match_result|
id = match_result.id
if counter.key? id
counter[id] += 1
else
counter[id] = 1
end
end
end
counter.map { |id, occurrences| { relevance: 100*(occurrences/4.0), customer: Customer.find(id) } }.sort_by { |r| r[:relevance] }.reverse!
end
end
Usage:
Customer.relevance_search ["John", "Doe", "111-111-1111"]
The return value is and array ordered by relevance in %
Enjoy :)