我如何在聚合函数的push运算符中使用数组，我得到了异常：聚合组运算符是一元（$ push）错误

Question

我想找到所有病历中cough和headache的病人

每个医疗记录都包含两个记录症状的字段，“SYMPTOM_1，SYMPTOM_2”

我通过以下查询查询，但是我收到了这个错误。

exception: aggregating group operators are unary ($push)

我希望在病历史上发现患者咳嗽和头痛

预期结果应为 Mary 和 Jack

咳嗽代码：cough_codes = ["477 ","4770 "] 头痛的代码：headache_codes = ["147 ","1470 "]

这是我的查询

cur= db_conn.medical_records.aggregate(
        [
            {"$match":{
                 "$and":[
                   {
                    "$or":[
                        {'SYMPTOM_1': '477  '},
                        {'SYMPTOM_2': '4770 '}
                      ]
                   },
                   {
                    "$or":[
                        {'SYMPTOM_1': '147  '},
                        {'SYMPTOM_2': '1470 '}
                      ]
                   },                   
                 ]
               }
            },        
            { "$sort": { "APPL_DATE": 1}},
            { "$group": 
                  {
                      "_id": "$ID", 
                      "dis": { "$push": ["$SYMPTOM_1","$SYMPTOM_2"] }
                  }
            }
        ]
    ) # end of aggregate query

医疗记录

{
    "id": 1,
    "name": "Mary",
    "SYMPTOM_1": "4770  ",
    "SYMPTOM_2": "477  ",
    "datetime": "2011-04-02"
},

{
    "id": 2,
    "name": "Jack",
    "SYMPTOM_1": "477  ",
    "SYMPTOM_2": "4770  ",
    "datetime": "2011-04-02"
},

{
    "id": 3,
    "name": "Mark",
    "SYMPTOM_1": "477  ",
    "SYMPTOM_2": "4770  ",
    "datetime": "2010-01-02"
},

....


{
    "id": 4,
    "name": "Jack",
    "SYMPTOM_1": "477  ",
    "SYMPTOM_2": "1470  ",    
    "datetime": "2015-04-09"
},

{
    "id": 5,
    "name": "Mary",
    "SYMPTOM_1": "477  ",
    "SYMPTOM_2": "147  ",    
    "datetime": "2010-09-02"
}

Answer 1

您需要指定＆＃34; _id＆＃34;在mongo查询中对数据进行分组。

根据提供的示例数据，您可以尝试以下操作：

db.collection.aggregate(
    [
        {"$match":{
             "$and":[
               {
                "$or":[
                    {'SYMPTOM_1': '477'},
                    {'SYMPTOM_2': '4770'}
                  ]
               },
               {
                "$or":[
                    {'SYMPTOM_1': '147'},
                    {'SYMPTOM_2': '1470'}
                  ]
               },                   
             ]
           }
        },        
        { "$sort": { "APPL_DATE": 1}},
        { "$group": 
              {
                  "_id": "$_id", 
                  "dis": {  "$push": { SYMPTOM_1: "$SYMPTOM_1", SYMPTOM_2: "$SYMPTOM_2" }}
              }
        }
    ]
    )

Answer 2

您可以使用累加器：

    Accumulators.push("dis", 
                    new BasicDBObject("SYMPTOM_1", "$SYMPTOM_1")
                        .append("SYMPTOM_2", "$SYMPTOM_2"))