javascript - 映射/组织 Node 中的嵌套对象

Question

我正在尝试自己映射嵌套对象，而不使用类似 JoinJS 的东西，这在一定程度上非常有效，直到我想正确地使我的 JSON 看起来很漂亮。

根据 SQL 查询，我的输出是:

[
  {
    "id": 1,
    "city_name": "city 1 - some city name",
    "city_category": "city 1 - some category",
    "city_description": "city 1 - some city description",
    "city_id": 1,
    "store_id": 1
  },
  {
    "id": 1,
    "city_name": "city 1 - some city name",
    "city_category": "city 1 - some category",
    "city_description": "city 1 - some city description",
    "city_id": 1,
    "store_id": 2
  },
  {
    "id": 1,
    "city_name": "city 1 - some city name",
    "city_category": "city 1 - some category",
    "city_description": "city 1 - some city description",
    "city_id": 1,
    "store_id": 3
  },
  {
    "id": 2,
    "city_name": "city 2 - some city name",
    "city_category": "city 2 - some category",
    "city_description": "city 2 - some city description",
    "city_id": 2,
    "store_id": 1
  },
  {
    "id": 2,
    "city_name": "city 2 - some city name",
    "city_category": "city 2 - some category",
    "city_description": "city 2 - some city description",
    "city_id": 2,
    "store_id": 2
  }
]

我试图让这个输出看起来像这样:

[
  {
    "city_id": 1,
    "city_name": "city 1 - some city name",
    "city_category": "city 1 - some category",
    "city_description": "city 1 - some city description",
    "store_ids": [1,2,3]
  }
  {
    "city_id": 2,
    "city_name": "city 2 - some city name",
    "city_category": "city 2 - some category",
    "city_description": "city 2 - some city description",
    "store_ids": [1,2]
  }
]

我的第一个猜测是我需要使用 _.chain(result).uniqBy(' 查找所有唯一的 id 或 city_id city_id').value()。但后来我有点坚持从输出中删除 id ，最重要的是，如何创建一个新的键 store_ids ，其中包含每个城市所有商店的数组。有道理吗？

使用Lodash或者只是普通的 JS(没有像 JoinJS 这样的其他模块，除非它们对于这样的事情是有效的)，我将如何操纵它？

Answer 1

我将运行结果，并将它们分组到我的新对象结果中。最后你将得到一个对象的对象，其键是item.id，但如果你想将它转换为数组，这很简单。

let resultsObject = {};

sqlQueryRows.map(function(item) {
   if (item.id in resultsObject) {
       resultsObject[item.id].store_ids.push(item.store_id);
   } else {
       resultsObject[item.id] = {
           city_id: item.city_id,
           city_name: item.city_name,
           city_category: item.city_category,
           city_description: item.city_description,
           store_ids: [item.store_id] 
       }
   }
});

// if you need an array
let resultsArray = Object.values(resultsObject);