猫鼬聚合内部查找按字段分组

Question

我正在尝试对所有不同的字段进行分组，然后查找另一个 table ，问题是我在查找中为同一用户添加了太多结果，所以我想知道如何才能在内部对这些结果进行分组，然后在下一阶段将另一个查找添加到不同的 table。目前我有以下代码：

Post.aggregate([
    { "$group" : {"_id" : { "id_fanpage": "$id_fanpage" },"total": { $sum: 1 } } },
    {
      "$lookup": {
        "from": "v3_post_reaccion_angry",
        "localField": "_id.id_fanpage",
        "foreignField": "id_fanpage",
        "as": "resultingAngries"
      }
    },
    {
      "$lookup": {
        "from": "v3_post_reaccion_compartir",
        "localField": "_id.id_fanpage",
        "foreignField": "id_fanpage",
        "as": "resultingCompartir"
      }
    }
  ]).exec(function(err, results){
    console.log(results);
    return results
  }).then(success(res))

我想要做的是通过 "id_fanpage" 区分 Post 行，然后通过返回的 id_fanpage 加入另一个 table 行，这基本上按预期工作，结果是这样的：

{
        "_id": {
            "id_fanpage": "5a63a96d1aa940ca0ada1c82"
        },
        "total": 831,
        "resultingAngries": [
            {
                "_id": "5a71ccda1aa940dd154caf83",
                "id_post": "5a71ccda1aa940dd154caf82",
                "id_fanpage": "5a63a96d1aa940ca0ada1c82",
                "facebook_usuario_id": 345346565665,
                "facebook_usuario_nombre": "AAAAAAAAAAAAAAAAA"
            },
            {
                "_id": "5a71cd6b1aa940dd154ddb43",
                "id_post": "5a71cd6b1aa940dd154ddb40",
                "id_fanpage": "5a63a96d1aa940ca0ada1c82",
                "facebook_usuario_id": "44444444444444444",
                "facebook_usuario_nombre": "XXXXXXXXXXXXXXXX"
            },
            {
                "_id": "5a71d7f61aa940dd156b60f4",
                "id_post": "5a71d7f61aa940dd156b60e9",
                "id_fanpage": "5a63a96d1aa940ca0ada1c82",
                "facebook_usuario_id": "asdf12345232421",
                "facebook_usuario_nombre": "YYYYYYYYYYYYYY"
            },
            {
                "_id": "5a71cde11aa940dd154ec514",
                "id_post": "5a71cde11aa940dd154ec513",
                "id_fanpage": "5a63a96d1aa940ca0ada1c82",
                "facebook_usuario_id": "asdf2345234555",
                "facebook_usuario_nombre": "ZZZZZZZZZZZZZZ"
            },
            {
                "_id": "5a71cdcb1aa940dd154e917a",
                "id_post": "5a71cdcb1aa940dd154e9178",
                "id_fanpage": "5a63a96d1aa940ca0ada1c82",
                "facebook_usuario_id": "44444444444444444",
                "facebook_usuario_nombre": "XXXXXXXXXXXXXXX"
            }
        ]
        }

现在的问题是，我想按 facebook_usuario_id 对 resultAngries 中的所有结果进行分组，并且还能够将其添加到下一次查找中，但据我所知我不能在之后使用分组第一次查找而不影响下一次查找。所以结果应该是：

{
        "_id": {
            "id_fanpage": "5a63a96d1aa940ca0ada1c82"
        },
        "total": 831,
        "resultingAngries": [
            {
                "_id": "this is my user id 1111111111",
                "count": N,
            },
            {
                "_id": "this is my user id 2222222222",
                "count": Y,
            }
         ],
        "resultingLikes": [
            {
                "_id": "this is my user id 1111111111",
                "count": N,
            },
            {
                "_id": "this is my user id 2222222222",
                "count": Y,
            }
         ],
   },
   {
    "_id": {
            "id_fanpage": "5a63a96d1aa942345wedf23455s"
        },
        "total": 20,
        "resultingLikes": [
            {
                "_id": "this is my user id 1111111111",
                "count": N,
            },
            {
                "_id": "this is my user id 2222222222",
                "count": Y,
            }
         ],
   },
     "resultingAngries": [
        {
            "_id": "this is my user id 1111111111",
            "count": N,
        },
        {
            "_id": "this is my user id 2222222222",
            "count": Y,
        }
     ],

等等。我已经看过聚合和查找，但不确定 $addToSet 是否可以做到，因为到目前为止我无法在内部分组，所以应用 addToSet 给我带来了困难。帮助将不胜感激。

Answer 1

在您的 $lookup 之间插入以下三个阶段。

下面的步骤 $unwind resultingAngries array followed by first $group to count the distinct combination of facebook_usuario_id & id_fanpage and second $group to $push 将 count 和 facebook_usuario_id 返回到 resultingAngries 数组。

  {"$unwind":"$resultingAngries"},
  {"$group":{
    "_id":{
      "id_fanpage":"$_id.id_fanpage",
      "facebook_usuario_id":"$resultingAngries.facebook_usuario_id"
    },
    "total":{"$first":"$total"},
    "count":{"$sum":1}
  }},
  {"$group":{
    "_id":{"id_fanpage":"$_id.id_fanpage"},
    "total":{"$first":"$total"},
    "resultingAngries":{
      "$push":{
        "_id":"$_id.facebook_usuario_id",
        "count":"$count"
      }
    }
  }}

猫鼬聚合内部查找按字段分组

Mongoose aggregate internal lookup grouping by field

lookup

grouping

aggregate

mongoose

mongodb