如何使用mongoose在mongoDB中使用字段计数来查询集合？

const mongoose = require('mongoose');

const yourSchema = new mongoose.Schema({
  field1: String,
  field2: Number,
  // 其他字段...
});

yourSchema.virtual('fieldCount').get(function() {
  return Object.keys(this._doc).length - 1; // 减去"_id"字段
});

const YourModel = mongoose.model('YourModel', yourSchema);

YourModel.aggregate([
  {
    $project: {
      fieldCount: {
        $size: {
          $objectToArray: '$$ROOT'
        }
      }
    }
  }
], function(err, result) {
  if (err) {
    console.error(err);
  } else {
    console.log(result);
  }
});