javascript - Mongo 填充可选字段，给出强制转换错误

Question

我有一个“vendor ”和“媒体”集合，媒体集合存储 vendor 配置文件图像，这不是 vendor 的必填字段。有些 vendor 有个人资料图片，有些没有，我想列出所有 vendor ，包括他们的个人资料图片引用。但是当我从 meidas 填充 profilePicture 时出现转换错误。我有其他填充，如“userId”、“venueId”，这些是必填字段，并且有效。

错误:CastError:对于模型“medias”未定义的路径“_id”处的值“xyz”，转换为 ObjectId 失败

查找查询:

const result = await resultObject.skip(skip)
    .populate('userId')
    .populate('venueId')
    .populate('profilePicture')
      .limit(parseInt(obj.pageSize, 10))
      .sort({ [obj.sortColumn]: parseInt(obj.sortValue, 10) });
    return result;

媒体模型

const MediasModel = () => {
  const MediasSchema = new mongoose.Schema({
    url: { type: String, required: true },
    key: { type: String},
  }, { timestamps: { createdAt: 'createdDate', updatedAt: 'modifedDate' } });
  return mongoose.model('medias', MediasSchema);
};

module.exports = MediasModel();

vendor 模型

const Vendors = new mongoose.Schema({
  venueId: { type: mongoose.Schema.Types.ObjectId, ref: 'venues' },
  userId: { type: mongoose.Schema.Types.ObjectId, ref: 'users' },
  name: { type: String, required: true },
  profilePicture: { type: mongoose.Schema.Types.ObjectId, ref: 'medias' },
}, { timestamps: { createdAt: 'createdDate', updatedAt: 'modifedDate' } });

module.exports = mongoose.model('vendors', Vendors);

Answer 1

尝试下面的代码

const Vendors = require('path/to/model_vendor');

Vendors.find()
.populate([{path: 'venues'}, {path: 'users'}, {path: 'medias'}])
.skip(skip_value)
.limit(limit_value)
.sort({condition: 1 }) // Modify according to your need
.exec().
.then(vendors=>{
console.log(vendors)
}).catch(err=>{
console.log(err)
})