Mongodb聚合嵌套组

Question

我在我的收藏中分配了人物，状态就像下面一样

[
 {"ASSIGN_ID": "583f84bce58725f76b322398", "STATUS": 1},
 {"ASSIGN_ID": "583f84bce58725f76b322398","STATUS": 4},
 {"ASSIGN_ID": "583f84bce58725f76b322398","STATUS": 4},
 {"ASSIGN_ID": "583f84bce58725f76b322398","STATUS": 3},
 {"ASSIGN_ID": "583f84bce58725f76b322311","STATUS": 1},
 {"ASSIGN_ID": "583f84bce58725f76b322311","STATUS": 3},
 {"ASSIGN_ID": "583f84bce58725f76b322322","STATUS": 1},
 {"ASSIGN_ID": "583f84bce58725f76b322322","STATUS": 4}
]

我想通过ASSIGN_ID对这些数据进行分组，并通过每个STATUS的STATUS计数对其进行分组，如下所示。

[  
   {  
      "ASSIGN_ID":"583f84bce58725f76b322398",
      "STATUS_GROUP":[  
         {  
            "STATUS":1,
            "COUNT":1
         },
         {  
            "STATUS":3,
            "COUNT":1
         },
         {  
            "STATUS":4,
            "COUNT":2
         }
      ]
   },
   {  
      "ASSIGN_ID":"583f84bce58725f76b322311",
      "STATUS_GROUP":[  
         {  
            "STATUS":1,
            "COUNT":1
         },
         {  
            "STATUS":3,
            "COUNT":1
         }
      ]
   },
   {  
      "ASSIGN_ID":"583f84bce58725f76b322322",
      "STATUS_GROUP":[  
         {  
            "STATUS":1,
            "COUNT":1
         },
         {  
            "STATUS":4,
            "COUNT":1
         }
      ]
   }
]

但是，我有编写代码，它只按STATUS分组。 请在下面找到查询。

Inspection.aggregate([
    {$group: {
    "_id": '$STATUS',
    "count" :  { $sum : 1 }}}], function (err, result) {
}});

请帮我解决这个问题。

Answer 1

使用此命令，它将适用于您的示例案例，希望它能解决您的问题，

db.testCollection.aggregate([{
    $group: {
        _id: {
            ASSIGN_ID: "$ASSIGN_ID",
            STATUS: "$STATUS"
        },
        count: {
            "$sum": 1
        }
    }
}, {
    $group: {
        _id: "$_id.ASSIGN_ID",
        STATUS_GROUP: {
            $push: {
                STATUS: "$_id.STATUS",
                count: "$count"
            }
        }
    }
}])

shell输出：

{
    "_id": "583f84bce58725f76b322398",
    "STATUS_GROUP": [{
        "STATUS": 3,
        "count": 1
    }, {
        "STATUS": 4,
        "count": 2
    }, {
        "STATUS": 1,
        "count": 1
    }]
}, {
    "_id": "583f84bce58725f76b322311",
    "STATUS_GROUP": [{
        "STATUS": 3,
        "count": 1
    }, {
        "STATUS": 1,
        "count": 1
    }]
}, {
    "_id": "583f84bce58725f76b322322",
    "STATUS_GROUP": [{
        "STATUS": 1,
        "count": 1
    }, {
        "STATUS": 4,
        "count": 1
    }]
}