Group Rails按属性查询数组

Question

假设我有这些行:(表示为JSON）：

[
  { name: "Bob", age: 10 },
  { name: "Carl", age: 15 },
  { name: "Alice", age: 10 },
  { name: "Derek", age: 20 }
]

我如何在Rails中按age分组？例如，我想要这样的东西：

[
  { age: 10, objects: [
    { name: "Bob", age: 10 },
    { name: "Alice", age: 10 }
  ] },
  { age: 15, objects: [
    { name: "Carl", age: 15 }
  ] },
  { age: 20, objects: [
    { name: "Derek", age: 20 }
  ] },
]

Answer 1

知道了！

People.all.group_by(&:age)

Answer 2

如果您实际上正在处理JSON：

people.group_by{|p| p['age'] }

如果您正在处理ActiveRecord模型：

People.group('id, age')

Here还有关于使用ActiveRecord进行分组的其他文档。