lodash groupby item.product_id 可能吗？

Question

我有一个这样的数组：

    Array [
      Object {
        "item": Object {
          "amount": 1,
          "price": 29.99,
          "product_id": 5,
          "product_name": "Calvin klein Bag",
          "username": "Ester71",
        },
        "type": "NORMAL",
      },
      Object {
        "item": Object {
          "amount": 1,
          "price": 29.99,
          "product_id": 3,
          "product_name": "Calvin klein Bag",
          "username": "Ester71",
        },
        "type": "NORMAL",
      },
      Object {
        "item": Object {
          "amount": 1,
          "price": 29.99,
          "product_id": 5,
          "product_name": "Calvin klein Bag",
          "username": "Ester71",
        },
        "type": "NORMAL",
      },
    ],

我想要 groupby product_id。但它不起作用。

这是一个带有颜色的示例。它可以工作，如果我删除上面数组中的项目，那么它也可以工作，但项目必须在那里做。

var data = [{
  "name": "jim",
  "color": "blue",
  "age": "22"
}, {
  "name": "Sam",
  "color": "blue",
  "age": "33"
}, {
  "name": "eddie",
  "color": "green",
  "age": "77"
}];

console.log(
  _.chain(data)
    // Group the elements of Array based on `color` property
    .groupBy("color")
    // `key` is group's name (color), `value` is the array of objects
    .map((value, key) => ({ color: key, users: value }))
    .value()
);

那么我现在如何按 item.product_id 分组？

Answer 1

你可以试试这个

const data = [
  {
    "item":  {
      "amount": 1,
      "price": 29.99,
      "product_id": 5,
      "product_name": "Calvin klein Bag",
      "username": "Ester71",
    },
    "type": "NORMAL",
  },
   {
    "item":  {
      "amount": 1,
      "price": 29.99,
      "product_id": 3,
      "product_name": "Calvin klein Bag",
      "username": "Ester71",
    },
    "type": "NORMAL",
  },
   {
    "item": {
      "amount": 1,
      "price": 29.99,
      "product_id": 5,
      "product_name": "Calvin klein Bag",
      "username": "Ester71",
    },
    "type": "NORMAL",
  },
]

const groupBy = (product) => product.item.product_id

console.log(
  _.chain(data)
  .groupBy(groupBy)
  .map((value, key) => ({ product_id: key, products: value }))
  .value()
);

<script src="https://cdn.jsdelivr.net/npm/lodash@4.17.21/lodash.min.js"></script>