使用groupBy时，我应该把它放在哪里？

Question

我正在通过DataWeave教程(极力推荐的！)在dwlang.fun上学习，最后我被“与对象一起工作”章节的“拔取”部分搞糊涂了。输入是一个由四个命令行组成的数组，我需要按顺序id对其进行分组。输入是

[
  {
    "orderId"  : 1,
    "customer" : "Josh",
    "lineId"   : 1,
    "lineItem" : "Shoes",
    "price"    : 50
  },
  {
    "orderId"  : 1,
    "customer" : "Josh",
    "lineId"   : 2,
    "lineItem" : "Socks",
    "price"    : 20
  },
  {
    "orderId"  : 2,
    "customer" : "Mariano",
    "lineId"   : 3,
    "lineItem" : "Shirt",
    "price"    : 30
  },
  {
    "orderId"  : 2,
    "customer" : "Mariano",
    "lineId"   : 4,
    "lineItem" : "Jacket",
    "price"    : 80
  }
]

所需的输出是一个单独的数组，其中包含其自己数组中的每个顺序：

[
  [
    {
      "orderId": 1,
      "customer": "Josh",
      "lineId": 1,
      "lineItem": "Shoes",
      "price": 50
    },
    {
      "orderId": 1,
      "customer": "Josh",
      "lineId": 2,
      "lineItem": "Socks",
      "price": 20
    }
  ],
  [
    {
      "orderId": 2,
      "customer": "Mariano",
      "lineId": 3,
      "lineItem": "Shirt",
      "price": 30
    },
    {
      "orderId": 2,
      "customer": "Mariano",
      "lineId": 4,
      "lineItem": "Jacket",
      "price": 80
    }
  ]
]

我的代码已接近，但分组已关闭。我的代码是

%dw 2.0
output json
var myData = payload
    map (order, index) -> {
        (order pluck (v, k, idx) -> {
            (k): v
        })
  }
---
myData groupBy ((order, index) -> order.orderId)

我的产出是：

{
  "1": [
    {
      "orderId": 1,
      "customer": "Josh",
      "lineId": 1,
      "lineItem": "Shoes",
      "price": 50
    },
    {
      "orderId": 1,
      "customer": "Josh",
      "lineId": 2,
      "lineItem": "Socks",
      "price": 20
    }
  ],
  "2": [
    {
      "orderId": 2,
      "customer": "Mariano",
      "lineId": 3,
      "lineItem": "Shirt",
      "price": 30
    },
    {
      "orderId": 2,
      "customer": "Mariano",
      "lineId": 4,
      "lineItem": "Jacket",
      "price": 80
    }
  ]
}

Answer 1

我不确定myData是否有用，我删除了它。我在groupBy()之后使用了pluck()来收集每个组键的值，这似乎是预期的结果：

%dw 2.0
output application/json
---
payload 
    groupBy ((order, index) -> order.orderId)
    pluck ((value, key, index) -> value)

Answer 2

这里有一个替代的解决方案(没有拔掉)

%dw 2.0
output application/json
var groupedOrders=payload groupBy (item, index) -> item.orderId
---
(groupedOrders mapObject(v0,k0) ->
{
    'key':(v0)
}).*'key'