MongoDB-在父文档中填充GridFS文件元数据 [英] MongoDB - Populate GridFS files metadata in parent document

问题描述

我将NodeJS与Express，MongoDB，Mongoose和GridFS一起用于上载和检索文件.

I am using NodeJS with Express, MongoDB, Mongoose and GridFS for uploading and retrieving files.

我想通过ID引用其他文档中的文件，并在查询其他文档时填充文件元数据.

I would like to reference files in other documents by ID and populate the files metadata when querying the other documents.

例如:如果我有一个用户"集合，其中包含这样的文档...

For example: If I have a collection "users" with documents like this ...

{
   _id:   ObjectId("554dfeb59e78d9081af2404f"),
   name:  "John Doe",
   image: ObjectId("55b61ae329c44b483665bafc")
}

...我想做这样的事...

... I want to do somethig like this ...

User.findById(req.params.id)
  .populate('image')
  .exec(function(err, user) {...})

...这应该使我可以访问文件元数据-例如文件名...

... which should give me access to the files metadata - for example the filename ...

user.image.filename

有什么想法吗?

推荐答案

您可以为GridFS元数据集合定义一个架构，并在用户架构中引用它:

You can define a schema for the GridFS metadata collection and refer it in the User schema:

//define Model for metadata collection.
var GFS = mongoose.model("GFS", new Schema({}, {strict: false}), "fs.files" );

var UserSchema = Schema({
    image: {type: Schema.Types.Object, ref: 'GFS' } // refer the model
});

var User = mongoose.model('User', UserSchema);

User.findById(req.params.id)
  .populate('image') //populate 
  .exec(function(err, user) {...})

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