如何限制mongodb中的更新文件数量

const MongoClient = require('mongodb').MongoClient;

const url = 'mongodb://localhost:27017';
const dbName = 'myproject';

const client = new MongoClient(url, { useNewUrlParser: true, useUnifiedTopology: true });

client.connect((err) => {
  if (err) {
    console.error(err);
    client.close();
    return;
  }

  const db = client.db(dbName);
  const collection = db.collection('users');

  collection.updateMany(
    { name: 'John' },
    { $set: { age: 30 } },
    { writeConcern: { j: 1 } }
  )
  .then(results => {
    console.log('Updated documents count:', results.modifiedCount);
    client.close();
  })
  .catch(err => {
    console.error(err);
    client.close();
  });
});

const MongoClient = require('mongodb').MongoClient;

const url = 'mongodb://localhost:27017';
const dbName = 'myproject';

const client = new MongoClient(url, { useNewUrlParser: true, useUnifiedTopology: true });

client.connect((err) => {
  if (err) {
    console.error(err);
    client.close();
    return;
  }

  const db = client.db(dbName);
  const collection = db.collection('users');

  collection.insertMany(
    [
      { name: 'John', age: 30 },
      { name: 'Jane', age: 25 },
    ],
    { ordered: true, writeConcern: { j: 1 } }
  )
  .then(results => {
    console.log('Inserted documents count:', results.insertedCount);
    client.close();
  })
  .catch(err => {
    console.error(err);
    client.close();
  });
});