使用猫鼬转换一系列文档 [英] Transform an array of documents using mongoose

问题描述

我正在运行一个特殊的查询，我想在此之后转换结果.

I am running a special query in which I want transform the results after.

User.find({}, function(err, users) {
  // I want to remove/add some properties from/to each user here
});

有没有一种方法可以转换一系列文档?同样，这是一个特例，因此我不想对Schema进行转换，我认为该转换会像我想要的那样转换每个文档，但也会影响对User模型的所有其他查询.

Is there a way to transform an array of documents? Also this is a special case so I do not want to apply a transformation to the Schema, which I think would transform each document like I want, but would also affect all other queries to the User model.

基本上，我希望能够对返回的文档数组执行一次性转换.

Basically I want the ability to perform a one time transformation on the array of docs returned.

User.find({}, function(err, users) {
  // I want to remove/add some properties to each user here
  users.toJSON({transform: function(doc,ret,options) { /* do tranform*/ });
  // That will not work as I get an error that toJSON is not defined for that
  // array that was returned.
});

我可以通过在查询之前添加一个转换，然后在查询完成后删除该转换来伪造它，但这是非常糟糕的hack恕我直言.

I might be able to fake it out by adding a transformation right before I query and then removing that transformation when the query is complete, but that is a pretty bad hack IMHO.

想法?我是否错过了文档中的某些内容?

Ideas? Did I miss something in the docs?

推荐答案

您可以使用 lean 查询，以便从查询中返回纯JS对象数组，然后使用

You can use a lean query so that an array of plain JS objects are returned from the query and then use map to transform the array:

User.find({}).lean().exec(err, users) {
    users = users.map(function(user) {
        // transform user into newuser as needed.
        ...
        return newuser;
    });
});

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