Question

我想对数组进行计数。这是我的模特

modelDetail.aggregate([
            {
                $group: {
                    _id: '$main_section.dept',  
                    count: {$sum: 'first_array.second_array.main_data'}
                }
            }
        ], function (err, result) {
                if (err) {
                    //next(err);
                    console.log(err);
                } else {
                    console.log(JSON.stringify(result));
                    res.json(result);
                }
        });

这将为所有结果带来0。输出低于

[{"_id":"design","count":0},
{"_id":"training","count":0},
{"_id":"forecast","count":0},
{"_id":"internal audit","count":0},
{"_id":"research","count":0}]

我想获取所有数据的计数

这是我的模式

var userSchema = mongoose.Schema({
    main_section        :{
        dept            : String
    },

    first_array :[{//
        floor           : String,
        second_array            :[{//3rd level
            name                : String,//4th level
            date            : String
        }]
    }]
});

this is the data in the json

{ "_id" : "5bb39baf40f87f17f01734f8",
    "main_section" : {
        "dept" : "design"
    }, 
    "first_array" : [{ "_id" : "5bb39baf40f87f17f01734fc",  "floor" : "2nd floor" ,
        "second_array" : [
            { "_id" : "5bc102f6dff41a0e844dd2b7", "name" : "Blake Tyson", "date" : "2018-10-12T00:00:00Z" }, 
            { "_id" : "5bc102fddff41a0e844dd2bb", "name" : "Meagan Shawn", "date" : "2018-10-12T00:00:00Z" }, 
            { "_id" : "5bc1044dbba8b31ed42e7408", "name" : "Stephen Stone", "date" : "2018-10-12T00:00:00Z" }
        ]
    }]
},
{ "_id" : "5bb39baf40f87f17f01734f8",
    "main_section" : {
        "dept" : "training"
    }, 
    "first_array" : [{ "_id" : "5bb39baf40f87f17f01734fc",  "floor" : "1st floor",
        "second_array" : [
            { "_id" : "5bc102f6dff41a0e844dd2b7", "name" : "Micheal Harrison", "date" : "2018-10-12T00:00:00Z" }, 
            { "_id" : "5bc102fddff41a0e844dd2bb", "name" : "Favour Reality", "date" : "2018-10-12T00:00:00Z" }, 
            { "_id" : "5bc1044dbba8b31ed42e7108", "name" : "Gift Myers", "date" : "2018-10-12T00:00:00Z" }, 
            { "_id" : "5bc1044dbba8b31ed42e71a1", "name" : "Drake Hills", "date" : "2018-10-12T00:00:00Z" }, 
            { "_id" : "5bc1044dbba8b31ed42e74c2", "name" : "Hashtan Priest", "date" : "2018-10-12T00:00:00Z" }
        ]
    }]
},
{ "_id" : "5b98987f08925c0f5cd86780", 
    "main_section" : {
        "dept" : "forecast"
    }, 
    "first_array" : [{ "_id" : "5b98987f08925c0f5cd86784", "floor" : "4th floor",
        "second_array" : [ ]
    }]
},
{ "_id" : "5b98187f08924c0f5ad86790", 
    "main_section" : {
        "dept" : "internal audit"
    }, 
    "first_array" : [{ "_id" : "5b98987f08925c0f5cd86784", "floor" : "4th floor",
        "second_array" : [ ] 
    }]
},
{ "_id" : "5b98187f08924c0f5ad86790", 
    "main_section" : {
        "dept" : "research"
    }, 
    "first_array" : [{ "_id" : "5b98987f08925c0f5cd86784", "floor" : "4th floor",
        "second_array" : [ ] 
    }]
}

基本上我希望做的是让每个数组产生元素总数在数组中与主要部分并排第二设计将输出3 训练将输出5 预测将输出0 内部审核将输出0 研究将输出0

因此，我们非常感谢您的帮助！

计算内部数组猫鼬

0 个答案: