按多个属性（包括嵌套属性）对对象进行分组并汇总它们的值

Question

类似于Group objects by multiple properties in array then sum up their values ，但具有嵌套元素且更复杂。我已经挣扎了好几个小时了。

我有一系列产品：

产品看起来像这样：

{
    "commissioningDate": "2019-09-27",
    "_product": {
        "_id": "aaa",
        "name": "Installation"
    },
    "zones": [
        {
            "_zone": {
                "_id": "KK",
                "name": "Zone kk"
            },
            "category": "category1",
            "zone_quantity": 6
        }
    ],
    "product_quantity": 3
}

预期行为

我做了这个gist，因为示例太长了。

问题

所以我有一系列产品。

1) 仅当 commissioningDate 和 _product._id 相同时，此数组中的产品才被视为重复产品

2) 如果多个产品合并为一个产品：

• 我们需要一个总结product_quantity
• 如果可能，我们需要合并产品内的区域数组，否则将其添加到数组中

3) 仅当 _zone._id 和 category 相同时，此数组中合并产品的区域才被视为​​重复

4) 如果许多区域被合并到一个区域中，我们需要一个总结zone_quantity

Answer 1

假设您的单个产品区域的长度始终为 1。

const sample = [
    {
        "commissioningDate": "2019-09-27",
        "_product": {
            "_id": "aaa",
            "name": "Installation"
        },
        "zones": [
            {
                "_zone": {
                    "_id": "KK",
                    "name": "Zone kk"
                },
                "category": "category1",
                "zone_quantity": 6
            }
        ],
        "product_quantity": 3
    },
    {
        "commissioningDate": "2019-09-27",
        "_product": {
            "_id": "aaa",
            "name": "Installation"
        },
        "zones": [
            {
                "_zone": {
                    "_id": "KK",
                    "name": "Zone kk"
                },
                "category": "category2",
                "zone_quantity": 3
            }
        ],
        "product_quantity": 2
    },
    {
        "commissioningDate": "2019-09-27",
        "_product": {
            "_id": "aaa",
            "name": "Installation"
        },
        "zones": [
            {
                "_zone": {
                    "_id": "KK",
                    "name": "Zone kk"
                },
                "category": "category2",
                "zone_quantity": 4
            }
        ],
        "product_quantity": 5
    },
    {
        "commissioningDate": "2019-09-27",
        "_product": {
            "_id": "aaa",
            "name": "Installation"
        },
        "zones": [
            {
                "_zone": {
                    "_id": "CC",
                    "name": "Zone cc"
                },
                "category": "category2",
                "zone_quantity": 6
            }
        ],
        "product_quantity": 1
    },
    {
        "commissioningDate": "2019-09-27",
        "_product": {
            "_id": "bbbb",
            "name": "Installation"
        },
        "zones": [
            {
                "_zone": {
                    "_id": "CC",
                    "name": "Zone cc"
                },
                "category": "category2",
                "zone_quantity": 8
            }
        ],
        "product_quantity": 2
    },
    {
        "commissioningDate": "2019-09-26",
        "_product": {
            "_id": "bbbb",
            "name": "Installation"
        },
        "zones": [
            {
                "_zone": {
                    "_id": "CC",
                    "name": "Zone cc"
                },
                "category": "category2",
                "zone_quantity": 8
            }
        ],
        "product_quantity": 2
    }
]

//reduce initialze value is an empty object
const res = sample.reduce((group, item) => {
  //for each item, generate a key k by combining item commissioningDate and item _product._id seperated //by a comma 
  const k = `${item.commissioningDate},${item._product._id}`;
  
  //check if this key k exists in our object group(which is an empty object when we check the first //item)
  //if it is not in the object, we save the key k and its value which is current item into the object //group
  if(!group[k]) group[k] = Object.assign({}, item);
  
  //if it is in the object already 
  else{
  
  //we sum up current item quantity to the group of this item
    group[k].product_quantity+=item.product_quantity;
    
    //find index of zone in current group zones has the same zone id and category as item's
    for(const itemZone of item.zones){
      const zoneIdx = group[k].zones.findIndex(zone => zone._zone._id === itemZone._zone._id && zone.category === itemZone.category)

      //index is -1, it's not in group zones, we push the zone to group zones array
      if(zoneIdx === -1){
        group[k].zones.push(itemZone)
      }
      //in group zones, we sum up zone_quantity
      else{
        group[k].zones[zoneIdx].zone_quantity += itemZone.zone_quantity
      }
    }
    
  }
  //update current group
  return group
}, {})

//recall keys are our custom identifier for different groups of items, values are actually groups of //items, so we only need to get values from group object
console.log(Object.values(res))