按人口分组

Question

我正在尝试使用Mongoose和Node.js在MongoDB中使用填充操作进行groupBy。

我有一个单独的集合，其中包含client_id和project_id。一个客户可以有很多项目，这就是为什么我创建了另一个集合以便更好地理解的原因：

var CustomerHasProjectSchema = new mongoose.Schema({
    client_id: {type: mongoose.Schema.Types.ObjectId, ref: 'Customer'},
    project_id: {type: mongoose.Schema.Types.ObjectId, ref: 'Project'},
    txn_date: {
        type: Date,
        default: Date.now
    },
    status: {
        type: Number,
        default : 1
    }
});

我正在尝试做类似

的事情

  

GROUPBY（CLIENT_ID）    并填充（user_id）

我尝试的确切查询是

return customerHasProject.aggregate(
    [
        {
            $match: { 
                $and: [
                    { client_id: id }
                ]
            }
        },
        {
            $group : {
                 _id : "$client_id",
                 count: {
                    $sum: 1
                }
            } 
        },
        {
            $lookup: {
                from: "project",
                localField: "project_id",
                foreignField: "_id",
                as: "projects"
            }
        },
        {
            $unwind : { 
                "path" : "$project_id"
            }
        }
    ]

我在另一个StackOverflow post的帮助下尝试了这个。

我也尝试过：

return customer2.default.find({'_id' : req.params.id}).exec().then(response=>{
    project2.default.find({'client_id' : response[0]._id}).populate('client_id').then(customerWithProject=>{
        res.json(customerWithProject)
    })
})

但是这会在每个项目中返回客户端详细信息，结果如下：

[
    {
        _id: "5883b189872c7d00042e1630",
        projectTitle: "Marketing Analytics",
        client_id: {
            _id: "58833d9e1079ba000445a3a1",
            clientName: "Anil",
            companyName: "fgjhtrjhed",
            website: "jhtryjh",
            clientEmail: "frhyrt@tyhtr.dfkgjoiu",
            mobileNumber: 549821654,
            companyLocation: "New Delhi, Delhi, India",
            clientCategory: "Freelancer",
            __v: 0,
            status: 1,
            txn_date: "2017-01-21T10:53:18.360Z"
        },
        start_date: "2017-01-21T18:30:00.000Z",
        end_date: "2017-01-30T18:30:00.000Z",
        domain: "Back to the Future",
        proposed_amount: 138000,
        expectedFinalAmount: 200000,
        __v: 0,
        status: 1,
        txn_date: "2017-01-21T19:07:53.214Z",
        keywords: [
            "JavaScript",
            "AngularJs",
            "C"
        ]
    },
    {
        _id: "5883b213872c7d00042e1631",
        projectTitle: "Indus Milk",
        client_id: {
            _id: "58833d9e1079ba000445a3a1",
            clientName: "Anil",
            companyName: "fgjhtrjhed",
            website: "jhtryjh",
            clientEmail: "frhyrt@tyhtr.dfkgjoiu",
            mobileNumber: 549821654,
            companyLocation: "New Delhi, Delhi, India",
            clientCategory: "Freelancer",
            __v: 0,
            status: 1,
            txn_date: "2017-01-21T10:53:18.360Z"
        },
        domain: "Back to the Future",
        start_date: "2017-01-01T18:30:00.000Z",
        end_date: "2017-01-06T18:30:00.000Z",
        proposed_amount: 9200,
        expectedFinalAmount: 15000,
        __v: 0,
        status: 1,
        txn_date: "2017-01-21T19:10:11.403Z",
        keywords: [
            "Java",
            "JavaScript"
        ]
    },
    {
        _id: "5883b817872c7d00042e1632",
        proposed_amount: 120000,
        start_date: "2017-01-09T18:30:00.000Z",
        end_date: "2017-02-03T18:30:00.000Z",
        domain: "Back to the Future",
        client_id: {
            _id: "58833d9e1079ba000445a3a1",
            clientName: "Anil",
            companyName: "fgjhtrjhed",
            website: "jhtryjh",
            clientEmail: "frhyrt@tyhtr.dfkgjoiu",
            mobileNumber: 549821654,
            companyLocation: "New Delhi, Delhi, India",
            clientCategory: "Freelancer",
            __v: 0,
            status: 1,
            txn_date: "2017-01-21T10:53:18.360Z"
        },
        projectTitle: "Something",
        __v: 0,
        status: 1,
        txn_date: "2017-01-21T19:35:51.835Z",
        keywords: [
            "C++",
            "C"
        ]
    }
]

期待像

这样的东西

[
    {
        client_id: {
            _id: "58833d9e1079ba000445a3a1",
            clientName: "Anil",
            companyName: "fgjhtrjhed",
            website: "jhtryjh",
            clientEmail: "frhyrt@tyhtr.dfkgjoiu",
            mobileNumber: 549821654,
            companyLocation: "New Delhi, Delhi, India",
            clientCategory: "Freelancer",
            __v: 0,
            status: 1,
            txn_date: "2017-01-21T10:53:18.360Z"
        },
        project_id : [
            {
                _id: "5883b213872c7d00042e1631",
                projectTitle: "Indus Milk",
                domain: "Back to the Future",
                start_date: "2017-01-01T18:30:00.000Z",
                end_date: "2017-01-06T18:30:00.000Z",
                proposed_amount: 9200,
                expectedFinalAmount: 15000,
            },{
                _id: "5883b817872c7d00042e1632",
                proposed_amount: 120000,
                start_date: "2017-01-09T18:30:00.000Z",
                end_date: "2017-02-03T18:30:00.000Z",
                domain: "Back to the Future",
                projectTitle: "Something",
                expectedFinalAmount: 15000,
            }
        ]
    }
]