Mongoose 返回的数据是不可变的吗? [英] Is data returned from Mongoose immutable?

问题描述

我想添加到来自猫鼬查询的返回数据:

I want to add to the return data from a mongoose query:

User.findById(userId, function(err, data) {
  if (!err) {
    data.newvar = 'Hello, world';
  }
});

但是，当我控制台记录输出时，newvar 不存在.我也尝试过使用 Underscore 的扩展:

However, when I console log the output, the newvar does not exist. I've also tried this using Underscore's extend:

_.extend(data, {'newvar': 'Hello, world'});

也没有运气.因为我有嵌套文档，所以使用浅拷贝是行不通的.有什么办法可以在这里追加数据吗?

With no luck either. Since I have nested documents, using a shallow copy won't work. Is there any way to append data here?

推荐答案

处理此问题的一种方法是通过调用 toObject() 就可以了:

One way to handle this is to convert your mongoose model instance into a plain object that you have full control over by calling toObject() on it:

User.findById(userId, function(err, data) {
  if (!err) {
    data = data.toObject();
    data.newvar = 'Hello, world';
  }
});

如果您想要更结构化的解决方案，您可以按照此处的说明向架构添加虚拟属性.

If you want a more structured solution, you can add virtual attributes to your schema as described here.

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