如何在哈希数组中分组

Question

我有很多哈希

并且我需要能够按用户对它们进行分组。

      order = Order.find(options[:order_id])
      shipments = order.shipments.select {|shipment| shipment["roundtrip_shipment"] == nil }.collect {|o| {
        id: o.id,
        user_id: o.user_id,
        ...
      } }

我在数组中进行分组时遇到了一些问题。

我已经尝试过进行shipments = order.shipments.group_by { |shipment| shipment[:user_id] }.count shipments = order.shipments.group_by { |shipment| shipment[:user_id] }.count

但是当我知道这里有2个用户时，它总是返回1。感谢所有帮助

Answer 1

您可以简单地执行以下操作：

order = Order.find(options[:order_id])
shipments = order.shipments.where.not(roundtrip_shipment: nil).group_by(&:user_id).collect {|x,y| {x => y.map(&:id)} }