How to change a key-value pair of a hash in Ruby? - arrays

Question

I have a query that returns an array and a hash.
How can I change the hash and add a new key-value pair to it: import_id: 1, cost: 0, or can I use a map method on the query?
The query is as follows.
name = Store.joins(:paid => :supply).group(:name).select("supply.name").where("stores.identifier IN (?) ", tids).pluck(:supply_id, :name)
The array is as follows.
[[258, "Square"], [245, "App"]]
When I convert it to a hash, it returns the following.
{258=>"Square", 245=>"App"}
The desired output is as follows.
{{supply_id: 258, name: "Square", import_id: 1, cost: 0}, {supply_id: 245, name: "App", import_id: 1, cost: 0}}

Answer 1

It appears the response is an array of [supply_id, name] pairs. You can easily destructure the array and restructure the data as hashes with proper symbolic keys.
array = [[258, "Square"], [245, "App"]]
array.map do |(id, name)|
{ supply_id: id, name: name, import_id: 1, cost: 0 }
end
# [{:supply_id=>258, :name=>"Square", :import_id=>1, :cost=>0}, ...]

Answer 2

Use #select instead of #pluck and call .as_json or .map(&:attributes)
Store.joins(:paid => :supply).group(:name)
.select("supply.name").where("stores.identifier IN (?) ", tids)
.select(:supply_id, :name).as_json
# [{supply_id: 258, name: "Square"}, {supply_id: 245, name: "App"}]
or
Store.joins(:paid => :supply).group(:name)
.select("supply.name").where("stores.identifier IN (?) ", tids)
.select(:supply_id, :name).map(&:attributes)
# [{supply_id: 258, name: "Square"}, {supply_id: 245, name: "App"}]
or you can construct Hash with {import_id: 1, cost: 0} appended
Store.joins(:paid => :supply).group(:name)
.select("supply.name").where("stores.identifier IN (?) ", tids)
.select(:supply_id, :name)
.map {|e| {supply_id: e.supply_id, name: e.name, import_id: 1, cost: 0} }
# [{supply_id: 258, name: "Square", import_id: 1, cost: 0}, {supply_id: 245, name: "App", import_id: 1, cost: 0}]
or
You can use Hash#merge during Hash generation step to include {import_id: 1, cost: 0}
hash.merge({import_id: 1, cost: 0})
# To achieve: {{supply_id: 258, name: "Square", import_id: 1, cost: 0}, {supply_id: 245, name: "App", import_id: 1, cost: 0}}