ddl.grn

table_create Books TABLE_HASH_KEY ShortText
column_create Books authors COLUMN_VECTOR ShortText

load --table Books
[
{"_key": "Hello Groonga", "authors": ["Taro", "Hanako"]},
{"_key": "The first step for Groonga", "authors": ["Taro"]},
{"_key": "Mastering Groonga", "authors": ["Hanako"]}
]

parse.rb

require 'ostruct'
require 'json'

cmd = "groonga /tmp/db"
query = "select Books --drilldown authors --command_version 3"
#query = "select Books --drilldowns[authors] authors --command_version 3"

ret = `#{cmd} #{query}`
results = JSON.parse ret

elapsed_time = results["header"]["elapsed_time"]
n_hits = results["body"]["n_hits"]

columns = results["body"]["columns"].map {|c| c["name"] }
docs = results["body"]["records"].map do |record|
  doc = {}
  record.each_with_index {|value, t| doc[columns[t]] = value }
  OpenStruct.new(doc)
end

puts n_hits
docs.each do |doc|
  puts "#{doc._key}: #{doc.authors}"
end

#n_hits = results["body"]["drilldowns"]["authors"]["n_hits"]
#columns = results["body"]["drilldowns"]["authors"]["columns"].map {|c| c["name"] }
#docs = results["body"]["drilldowns"]["authors"]["records"].map do |record|
#  doc = {}
#  record.each_with_index {|value, t| doc[columns[t]] = value }
#  OpenStruct.new(doc)
#end

#puts n_hits
#docs.each do |doc|
#  puts "#{doc._key}: #{doc._nsubrecs}"
#end