javascript - 如何使用 lodash 将对象中的数组数据与计数分组

Question

如何使用 lodash javascript 对数据进行分组

"data": [
            {
                "id": 27,
                "getOrderDetail": [
                    {
                        "id": 49,
                        "order_id": 27,
                        "product_id": 1,
                        "product_detail":[...some data...]
                    },
                    {
                        "id": 51,
                        "order_id": 27,
                        "product_id": 2,
                        "product_detail":[...some data...]
                    }
                    {
                        "id": 52,
                        "order_id": 27,
                        "product_id": 1,
                        "product_detail":[...some data...]
                    }
                ],
                "getOrderStatus": []
            },
        ]

我想在 getOrderDetail 中按 Product_id 进行分组，并将其计入数量，例如

"data": [
            {
                "id": 27,
                "getOrderDetail": [
                    {
                        "id": 49,
                        "qty": 2,
                        "order_id": 27,
                        "product_id": 1,
                        "product_detail":[...some data...]
                    },
                    {
                        "id": 51,
                        "order_id": 27,
                        "qty": 1,
                        "product_id": 2,
                        "product_detail":[...some data...]
                    }
                ],
                "getOrderStatus": []
            },
        ]

我想做这样的事情

_.countBy(data, 'getOrderDetail.product_id'); 并将数据计数放入 qty 字段

这是我尝试的

let result = _.map(totalData, function(totalData, key) {
        let mapData = _.groupBy(totalData.getOrderDetail, function({ product_id }) {
            return product_id;
        });
});

我的console.log(mapData)输出看起来像这样

{
  '1': [
    {
      id: 49,
      product_id: 1,
    }
  ],
  '2': [
    {
      id: 51,
      product_id: 2,
    }
  ]
}

仍然在寻找如何计算数量

Answer 1

您可以使用_.groupBy()，然后映射结果，并通过应用_.size()来获取qty组，并通过合并组成员、连接数组并传播回对象来获取 getOrderDetail:

const data = [{"id":27,"getOrderDetail":[{"id":49,"order_id":27,"product_id":1,"product_detail":[]},{"id":51,"order_id":27,"product_id":2,"product_detail":[]},{"id":52,"order_id":27,"product_id":1,"product_detail":[]}],"getOrderStatus":[]}];

const result = data.map(o => ({
  ...o,
  getOrderDetail: _.map(
      _.groupBy(o.getOrderDetail, 'product_id'),
      group => ({
        qty: _.size(groups),
        ..._.mergeWith({}, ...groups, (ov, sv) =>
          _.isArray(ov) ? ov.concat(sv) : sv
        )
      })
  )
}));

console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.js"></script>