Mongoose Implement Dbref Find all sub-class information

Product table

var Mongoose = require(‘mongoose‘);var Schema = Mongoose.Schema;var Product = new Schema({    image : {              type : String          },    description : {                      type : String                  },    price : {                type : Number,                require : true            },    probability : {                      type : Number,                      require : true                  },    status :{                type : Number,                require : true,                1            },    categoryId:{        type:String,        require:true    },    name : {        type :String,        require : true    }},{    _id : true,    autoIndex : true});module.exports = Mongoose.model(‘Product‘,Product);

Product Classification Table

    var Mongoose = require(‘mongoose‘);var Schema = Mongoose.Schema;var Category = new Schema({    child : [{        type : Schema.Types.ObjectId,        ‘Product‘    }],    name : {                type : String,                require : true           },    description : {                type : String,                require : true            },    image : {                type : String,                require : true            }},{    _id : true,    autoIndex : true});module.exports = Mongoose.model(‘Category‘,Category);

We insert the ID of the item into the category each time we add a product.

var product = new Product ({name:' Jurassic Coffee ', Image:'/3.jpg ', Descript:"It's still possible.", Price:50.00, Probability: -, Status:1, CategoryId:"552f76bd3e0b2dfca7989da3"}) Product.save (function (err) {if(ERR)        {Console.log (ERR); }Else{Category.find ({_id:"552f76bd3e0b2dfca7989da3"},function (err,result) {result[0].child.push (product._id); result[0].save (function (err) {Console.log (' ok! ')                })            })        }    })

Find information about multiple items at the same time when looking for a categorical information

Category.find().populate(‘child‘).exec().then(function(result){        console.log(result);            })

Let's look at the output:

[{_id:552F76bd3e0b2dfca7989da3, Image:'/1.jpg ', Description:' Our coffee is from Brazil, safe and pollution-free, dry, eat, eat. ', Name:' Coffee ', __v:7, child: [{_id:552f76a9b396a1e8651bba8d, Status:1}, {_id:552F76FF61D8370BA8490CEB, Name:' Tyrannosaurus rex Coffee ', Image:'/1.jpg ', Price: -, Probability: -, CategoryId:' 552f76bd3e0b2dfca7989da3 ', __v:0, Status:1}, {_id:552F773a12831318a8d51ce4, Name:' Sword-toothed dragon Coffee ', Image:'/2.jpg ', Price: the, Probability: -, CategoryId:' 552f76bd3e0b2dfca7989da3 ', __v:0, Status:1}, {_id:552f776a87443f28a8e66931, Name:' Tyrannosaurus rex Coffee ', Image:'/3.jpg ', Price: the, Probability: -, CategoryId:' 552f76bd3e0b2dfca7989da3 ', __v:0, Status:1}, {_id:552f777f87443f28a8e66932, Name:' Tyrannosaurus rex Coffee ', Image:'/3.jpg ', Price: the, Probability: -, CategoryId:' 552f76bd3e0b2dfca7989da3 ', __v:0, Status:1}, {_id:552F77846A87B934A8A45CFA, Name:' winged Dragon Coffee ', Image:'/3.jpg ', Price: -, Probability: -, CategoryId:' 552f76bd3e0b2dfca7989da3 ', __v:0, Status:1}, {_id:552F779CAD597A3FA8365F63, Name:' Chicken Coffee ', Image:'/3.jpg ', Price: -, Probability: -, CategoryId:' 552f76bd3e0b2dfca7989da3 ', __v:0, Status:1}, {_id:552F77ac294f5d4ba8006b27, Name:' Jurassic Coffee ', Image:'/3.jpg ', Price: -, Probability: -, CategoryId:' 552f76bd3e0b2dfca7989da3 ', __v:0, Status:1} ] } ]

Mongoose Implement Dbref Find all sub-class information