获取集合mongoose中所有文档的长度

const mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/your_database_name', { useNewUrlParser: true, useUnifiedTopology: true });

const Schema = mongoose.Schema;

const yourSchema = new Schema({
  // 定义集合中的字段
});

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

YourModel.find({}, (err, documents) => {
  if (err) {
    console.error(err);
  } else {
    const documentLength = documents.length;
    console.log(`集合中文档的长度为：${documentLength}`);
  }
});