我正在为项目使用 MongooseDeepPopulate包.我有SchemaA,SchemaB,SchemaC,SchemaD.我的SchemaD,SchemaC连接到SchemaB,SchemaB连接到SchemaA.
我这样做了.
var deepPopulate = require('mongoose-deep-populate')(mongoose);
AlbumSong.plugin(deepPopulate, {
populate: {
'song.category': {select: 'name status'},
'song.poetId': {select: 'name status'}
}
});
歌曲与类别和poetId进一步联系.我成功地限制了类别和poetId中的字段.但我希望限制中级模特歌曲中的字段.我的查询查询就像
AlbumSong.find(condition)
.deepPopulate('song.category song.poetId')
// .deepPopulate('song.category song.poetId' , '_id category poetId name nameHindi invalid status') // I tried this as well to limit records from song model as well.
.exec(function(err, playlist) {
callback(err, playlist);
});
在哪里我弄错了.
最佳答案 如果要限制AlbumSong的字段,可以使用 mongoose itself提供的功能,如下所示:
AlbumSong.find(condition)
.select('_id category poetId name nameHindi invalid status')
.deepPopulate(...)
Here is一个简单的应用程序来演示这个想法.
架构看起来像这样:
var userSchema = new Schema({
name: String,
email: String
});
var CommentSchema = new Schema({
author : {type: Schema.Types.ObjectId, ref: 'User'},
title: String,
body: String
})
var PostSchema = new Schema({
title: String,
author: { type: Schema.Types.ObjectId, ref: 'User' },
comments: [{type: Schema.Types.ObjectId, ref: 'Comment'}],
body: String
});
PostSchema.plugin(deepPopulate, {
populate: {
'author': { select: 'name' },
'comments': { select: 'title author' },
'comments.author': { select: 'name' },
}
});
上面的deepPopulate设置限制了相关作者,评论和comments.author的字段.
要获得帖子本身的帖子和限制字段,我使用这个:
Post.find().select('title author comments').deepPopulate('author comments.author').exec(function(err, data) {
// process the data
});
数据如下所示:
[{
"_id": "56b74c9c60b11e201fc8563f",
"author": {
"_id": "56b74c9b60b11e201fc8563d",
"name": "Tester"
},
"title": "test",
"comments": [
{
"_id": "56b74c9c60b11e201fc85640",
"title": "comment1",
"author": {
"_id": "56b74c9b60b11e201fc8563e",
"name": "Poster"
}
}
]
}]
所以对于帖子本身我们只有标题(未选择正文).
对于填充的记录,所选字段也是有限的.