Mongo ：分组并推送超过 1 个元素

Question

我有一个 mongodb 收集数据，如下所示；我想根据 EmployeedID（即 0001）对专业、代码和年龄字段进行分组。

{
"_id" : ObjectId("54d0512191a4da7736e9db43"),
"EmployeeID" : "0001",
"Speciality" : "xxx",
"Code" : "P",
"Age" : 8
}

/* 1 */
{
"_id" : ObjectId("54d0512191a4da7736e9db44"),
"EmployeeID" : "0002",
"Speciality" : "yyyyy",
"Code" : "P",
"Age" : 6
}

/* 2 */
{
"_id" : ObjectId("54d0512191a4da7736e9db45"),
"EmployeeID" : "0001",
"Speciality" : "zzz",
"Code" : "P",
"Age" : 5
}

我已经可以使用下面的方法（推送数组）基于 EmployeeID 对一个字段进行分组，即 Specialty。但是我不确定如何将其他字段（例如代码和年龄）添加到查询中？

collection.aggregate([{
    $match: {
        EmployeeID: '0001'
    }
}, {
    "$group": {
        "_id": "$EmployeeID",
        "speciality": {
            "$push": "$Speciality"
        }
    }
}], (function(err, docComp) {

      console.log("JSON.stringify" + JSON.stringify(docComp));

    }
}));

Answer 1

您可以将其汇总为：

collection.aggregate([
{$match:{"EmployeeId":1000}},
{$group:{"_id":"$EmployeeID",
            "speciality":{$push:"$Speciality"},
            "Code":{$push:"$Code"},
            "Age":{$push:"$Age"}}}
])

或者，

collection.aggregate([
{$match:{"EmployeeId":1000}},
{$group:{"_id":"$EmployeeID",
            "data":{$push:{"Speciality":"$Speciality",
                           "Code":"$Code",
                           "Age":"$Age"}}}}
])

Mongo ：分组并推送超过 1 个元素

Mongo : Group and push more than 1 element

javascript

mongodb

aggregation-framework