用Mongoose查询嵌套嵌入式文档
问题描述:
我想在嵌套嵌入式文档内查询。我试图“填充”结果,但是失败了。用Mongoose查询嵌套嵌入式文档
如何找回查找呼叫中的所有书籍详情?我想要一个用户书架上的所有书籍对象,我可以从中获取数据?
###
Trying to query nested embedded documents using Mongoose.
Database Outline for example
An Owner has multiple bookshelves which each have an array of books.
A book is not unique, and the same book could be on many different shelves.
###
mongoose = require("mongoose")
Schema = mongoose.Schema
mongoose.connect "localhost", "d1"
bookSchema = new Schema(title: String)
Book = mongoose.model("Book", bookSchema)
shelfBookSchema = new Schema(
book:
type: Schema.ObjectId
ref: "Book"
)
shelfSchema = new Schema(
name: String
books: [ shelfBookSchema ]
)
Shelf = mongoose.model("Shelf", shelfSchema)
ownerSchema = new Schema(
firstName: String
shelves: [ shelfSchema ]
)
Owner = mongoose.model("Owner", ownerSchema)
mongoose.connection.on "open", ->
book1 = new Book(title:"How to make stuff")
book1.save (err) ->
throw err if err
owner = new Owner(firstName:"John")
shelf = new Shelf(name:"DIY Shelf")
shelf.books.push
_id: book1._id
book: book1._id
owner.shelves.push shelf
owner.save (err) ->
throw err if err
#Let's find one owner and get all of his bookshelves and the books they containa
Owner.findOne().populate("shelves.books.book").exec (err, owner) ->
console.error owner.shelves[0].books
### Log shows:
{ book: 4fe3047401fc23e79c000003,
_id: 4fe3047401fc23e79c000003 }]
Great but how do I get the values of book like the title etc??
###
mongoose.connection.db.dropDatabase ->
mongoose.connection.close()
答
深人口在猫鼬3.6加入。 https://github.com/LearnBoost/mongoose/issues/1377#issuecomment-15911192
对于你的榜样,它会是这样的:
Owner.find().populate('shelves').exec(PopulateBooks);
function PopulateBooks(err, owners) {
if(err) throw err;
// Deep population is here
Book.populate(owners, { path: 'shelves.books' }).exec(callback);
}
+0
非常好的soluation !!!!! – Steven
+0
这似乎已在v3.6和v4.0.8之间发生变化。填充返回一个承诺,你可以传递一个函数:http://mongoosejs.com/docs/api.html#model_Model.populate –
这将是很好的接受支票移动到“深人口”的答案,现在解决了这个问题。 – JohnnyHK