如果键的数组中有值，则从mongodb的集合中删除元素

// 连接到MongoDB数据库
const MongoClient = require('mongodb').MongoClient;
const url = 'mongodb://localhost:27017';
const dbName = 'your_database_name';

MongoClient.connect(url, function(err, client) {
  if (err) throw err;

  // 选择要操作的集合
  const db = client.db(dbName);
  const collection = db.collection('your_collection_name');

  // 构建查询条件
  const query = { key: { $exists: true, $ne: [] } };

  // 删除满足条件的文档
  collection.deleteMany(query, function(err, result) {
    if (err) throw err;

    console.log(`${result.deletedCount} documents deleted.`);
    client.close();
  });
});