响应似乎是一个[supply_id, name]对的数组，您可以很容易地解构数组，并使用适当的符号键将数据重组为散列。

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}, ...]

使用#select代替#pluck，并调用.as_json或.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"}]

或

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"}]

也可以构造附加了{import_id: 1, cost: 0}的哈希

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}]

或
您可以在哈希生成步骤中使用Hash#merge来包含{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}}