是否有更好的方法来过滤GET调用中的数据，如下所示？(NodeJs & MongoDb)

const User = require('./models/user');

app.get('/users', async (req, res) => {
  const { userId } = req.query;
  const filter = userId ? { _id: userId } : {}; // 构建查询条件

  try {
    const users = await User.find(filter);
    res.json(users);
  } catch (error) {
    res.status(500).json({ error: 'Internal server error' });
  }
});

const userSchema = new mongoose.Schema({
  username: { type: String, required: true },
  // 其他字段...
});

userSchema.index({ username: 1 }); // 创建索引

const User = mongoose.model('User', userSchema);

app.get('/users', async (req, res) => {
  const { page = 1, pageSize = 10 } = req.query;
  const skip = (page - 1) * pageSize;

  try {
    const users = await User.find().skip(skip).limit(pageSize);
    res.json(users);
  } catch (error) {
    res.status(500).json({ error: 'Internal server error' });
  }
});