Question

我的Schema看起来像这样，其中关联的是String而不是_id的数组，而我使用Virtual方法填充了另一个{{ 1}}

Schema

我的const DetailSchema = mongoose.Schema({ candidate:{ . . associated: [String], . . } }, { toObject: { virtuals: true }, toJSON: { virtuals: true } });看起来像

Virtual

返回的字段始终为DetailSchema.virtual('associatedJobs', { ref: 'Jobs', localField: 'candidate.associated', foreignField: 'jobID', justOne: false });。有什么问题吗？

Answer 1

您应该同时提及两种架构结构以在查询中找到错误，我在虚拟字段中发表了一些示例，也许您会获得帮助

 const mongoose = require('mongoose');
    mongoose.Promise = global.Promise;
    mongoose.connect('mongodb://localhost:27017/test', { useMongoClient: true });

    var PersonSchema = new mongoose.Schema({
      name: String,
      band: String
    });

    var BandSchema = new mongoose.Schema({
      name: String
    }, { toObject: { virtuals: true } });
    BandSchema.virtual('members', {
      ref: 'Person', // The model to use
      localField: 'name', // Find people where `localField`
      foreignField: 'band', // is equal to `foreignField`
      // If `justOne` is true, 'members' will be a single doc as opposed to
      // an array. `justOne` is false by default.
      justOne: false
    });

    var Person = mongoose.model('Person', PersonSchema);
    var Band = mongoose.model('Band', BandSchema);

Answer 2

您对Jobs（ref: 'Jobs',）的引用，如果您声明模型为Job（可能不包含，则可能是ref: 'Job',（Job） '）

您的associatedJobs将不在对象中返回，这是示例，它可能采用以下格式：

{
    "candidate": {
        "associated": [
            "J2",
            "J3",
            "J5"
        ]
    },
    "_id": "5c1b4ab6683beb0b8162c80f",
    "id": "D1",
    "__v": 0,
    "associatedJobs": [
        {
            "_id": "5c1b4ab6683beb0b8162c80b",
            "jobID": "J2",
            "name": "Job name 2",
            "__v": 0
        },
        {
            "_id": "5c1b4ab6683beb0b8162c80c",
            "jobID": "J3",
            "name": "Job name 3",
            "__v": 0
        },
        {
            "_id": "5c1b4ab6683beb0b8162c80e",
            "jobID": "J5",
            "name": "Job name 5",
            "__v": 0
        }
    ]
}

这是我为您解决的问题的解决方案，您可以在gist上下载以在本地https://gist.github.com/huynhsamha/a728afc3f0010e49741ca627750585a0上运行

我的简单模式作为您的模式：

var DetailSchema = new Schema({
  id: String,
  candidate: {
    associated: [String]
  }
}, {
    toObject: { virtuals: true },
    toJSON: { virtuals: true }
});

var JobSchema = new Schema({
  jobID: String,
  name: String
});

DetailSchema.virtual('associatedJobs', {
  ref: 'Job',
  localField: 'candidate.associated',
  foreignField: 'jobID',
  justOne: false
});

var Detail = mongoose.model('Detail', DetailSchema);
var Job = mongoose.model('Job', JobSchema);

并且您应该在populate时添加 find ：

const d = await Detail.findOne({ id: 'D1' }).populate('associatedJobs');

嵌套字段返回null的猫鼬虚拟字段

2 个答案: