node.js - Mongoose 填充不填充嵌套数组数据
问题描述
所以我有这个用户模型,它指的是博客
用户模型
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const bcrypt = require("bcryptjs");
const userSchema = new Schema(
{
email: {
type: String,
required: true,
index: {
unique: true
}
},
password: {
type: String,
required: true
},
name: {
type: String,
required: true
},
website: {
type: String
},
bio: {
type: String
},
blogs: [
{
type: Schema.Types.ObjectId,
ref: "Blog"
}
]
},
{
timestamps: {
createdAt: "created_at",
updatedAt: "updated_at"
}
}
);
userSchema.pre("save", function(next) {
const user = this;
if (!user.isModified("password")) return next();
bcrypt.genSalt(10, function(err, salt) {
if (err) return next(err);
bcrypt.hash(user.password, salt, function(err, hash) {
if (err) return next(err);
user.password = hash;
next();
});
});
});
userSchema.methods.comparePassword = function(password, next) {
bcrypt.compare(password, this.password, function(err, isMatch) {
if (err) return next(err);
next(null, isMatch);
});
};
const User = mongoose.model("User", userSchema);
module.exports = User;
这是我的博客收藏,其中参考了评论模型
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const blogSchema = new Schema(
{
title: {
type: String,
required: true
},
body: {
type: String,
required: true
},
author: {
type: Schema.Types.ObjectId,
ref: "User"
},
likesCount: {
type: Number
},
comments: [
{
type: Schema.Types.ObjectId,
ref: "Comment"
}
]
},
{
timestamps: {
createdAt: "created_at",
updatedAt: "updated_at"
}
}
);
const Blog = mongoose.model("Blog", blogSchema);
module.exports = Blog;
这是我的评论模型,它参考了用户模型
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const CommentSchema = new Schema(
{
body: {
type: String,
required: true
},
likesCount: {
type: Number
},
user: {
type: Schema.Types.ObjectId,
ref: "User"
}
},
{
timestamps: {
createdAt: "created_at",
updatedAt: "updated_at"
}
}
);
const Comment = mongoose.model("Comment", CommentSchema);
module.exports = Comment;
我想要的是如果我获取用户数据我想获取博客以及评论数据我有这个代码
exports.getCurrentUser = async (req, res) => {
const ObjectId = mongoose.Types.ObjectId;
const users = await User.findById({ _id: new ObjectId(req.user._id) })
.populate({
path: "blogs",
model: "Blog"
})
.exec();
console.log(users);
return res.status(200).json(users);
};
但它没有填充博客
我怎样才能实现这种嵌套引用获取?
解决方案
我认为问题在于模型必须是模型引用,而不是模型名称。所以它必须model: Blog
代替model: "Blog"
.
另外我建议你重新设计你的模式,因为你在模型之间有很多引用。当您添加、插入或删除博客或评论时,您必须进行 2 次 db 调用。
我会从用户架构中删除博客字段,并从博客架构中删除评论字段,并像这样设置虚拟填充:
用户架构:
const userSchema = new Schema(
{
email: {
type: String,
required: true,
index: {
unique: true
}
},
password: {
type: String,
required: true
},
name: {
type: String,
required: true
},
website: {
type: String
},
bio: {
type: String
}
},
{
timestamps: {
createdAt: "created_at",
updatedAt: "updated_at"
},
toJSON: {
virtuals: true
}
}
);
userSchema.virtual("blogs", {
ref: "Blog",
foreignField: "author",
localField: "_id"
});
博客架构:
const blogSchema = new Schema(
{
title: {
type: String,
required: true
},
body: {
type: String,
required: true
},
author: {
type: Schema.Types.ObjectId,
ref: "User"
},
likesCount: {
type: Number
}
},
{
timestamps: {
createdAt: "created_at",
updatedAt: "updated_at"
},
toJSON: { virtuals: true }
}
);
blogSchema.virtual("comments", {
ref: "Comment",
foreignField: "blog",
localField: "_id"
});
请注意,我toJSON: { virtuals: true }
在两个模式中都添加了选项。
现在,您可以使用以下查询获取带有评论的用户博客:
const user = await User.findById(req.user._id)
.populate({
path: "blogs",
populate: "comments"
})
.select("-password")
.exec();
测试:
比方说你这些样本文件。
db={
"users": [
{
"_id": "5e53b1726f41c765fc4def9c",
"email": "user1@gmail.com",
"password": "$2a$10$.heEhkN2BhxZiw8upgjGQe.r3Gt78JVfuAqLqf6lHwireaKJSrrTO",
"name": "User1"
},
{
"_id": "5e53b1906f41c765fc4def9d",
"email": "user2@gmail.com",
"password": "$2a$10$tEaXpoeH5iXVzqmzozAFOOu.Nxb32Ssy1XS5CAqad7qqanHQkrqjK",
"name": "User2"
},
{
"_id": "5e53b1996f41c765fc4def9e",
"email": "user3@gmail.com",
"password": "$2a$10$4s34RLnSd75WeG8K.gzxxeixkruplzW0vpb7PJR/aL1d3Ia31wj.W",
"name": "User3"
}
],
"blogs": [
{
"_id": "5e53b26c6f41c765fc4def9f",
"title": "Blog1 Title",
"body": "Blog1 Body",
"author": "5e53b1726f41c765fc4def9c"
},
{
"_id": "5e53b2896f41c765fc4defa1",
"title": "Blog2 Title",
"body": "Blog2 Body",
"author": "5e53b1726f41c765fc4def9c"
}
],
"comments": [
{
"_id": "5e53b2f86f41c765fc4defa3",
"body": "Comment1 (user2 on user1's blog1)",
"user": "5e53b1906f41c765fc4def9d",
"blog": "5e53b26c6f41c765fc4def9f"
},
{
"_id": "5e53b3246f41c765fc4defa4",
"body": "Comment2 (user3 on user1's blog1)",
"user": "5e53b1996f41c765fc4def9e",
"blog": "5e53b26c6f41c765fc4def9f"
},
{
"_id": "5e53b34c6f41c765fc4defa5",
"body": "Comment3 (user2 on user1's blog2)",
"user": "5e53b1906f41c765fc4def9d",
"blog": "5e53b2896f41c765fc4defa1"
}
]
}
对于具有以下功能的用户,结果将如下所示_id: "5e53b1726f41c765fc4def9c"
:
{
"_id": "5e53b1726f41c765fc4def9c",
"email": "user1@gmail.com",
"name": "User1",
"created_at": "2020-02-24T11:20:18.343Z",
"updated_at": "2020-02-24T11:20:18.343Z",
"__v": 0,
"blogs": [
{
"_id": "5e53b26c6f41c765fc4def9f",
"title": "Blog1 Title",
"body": "Blog1 Body",
"author": "5e53b1726f41c765fc4def9c",
"created_at": "2020-02-24T11:24:28.895Z",
"updated_at": "2020-02-24T11:24:28.895Z",
"__v": 0,
"comments": [
{
"_id": "5e53b2f86f41c765fc4defa3",
"body": "Comment1 (user2 on user1's blog1)",
"user": "5e53b1906f41c765fc4def9d",
"blog": "5e53b26c6f41c765fc4def9f",
"created_at": "2020-02-24T11:26:48.506Z",
"updated_at": "2020-02-24T11:26:48.506Z",
"__v": 0
},
{
"_id": "5e53b3246f41c765fc4defa4",
"body": "Comment2 (user3 on user1's blog1)",
"user": "5e53b1996f41c765fc4def9e",
"blog": "5e53b26c6f41c765fc4def9f",
"created_at": "2020-02-24T11:27:32.305Z",
"updated_at": "2020-02-24T11:27:32.305Z",
"__v": 0
}
],
"id": "5e53b26c6f41c765fc4def9f"
},
{
"_id": "5e53b2896f41c765fc4defa1",
"title": "Blog2 Title",
"body": "Blog2 Body",
"author": "5e53b1726f41c765fc4def9c",
"created_at": "2020-02-24T11:24:57.078Z",
"updated_at": "2020-02-24T11:24:57.078Z",
"__v": 0,
"comments": [
{
"_id": "5e53b34c6f41c765fc4defa5",
"body": "Comment3 (user2 on user1's blog2)",
"user": "5e53b1906f41c765fc4def9d",
"blog": "5e53b2896f41c765fc4defa1",
"created_at": "2020-02-24T11:28:12.551Z",
"updated_at": "2020-02-24T11:28:12.551Z",
"__v": 0
}
],
"id": "5e53b2896f41c765fc4defa1"
}
],
"id": "5e53b1726f41c765fc4def9c"
}
另一种选择是使用 MongoDB 聚合框架。使用此选项,您可以删除我为虚拟填充添加的选项。
const users = await User.aggregate([
{
$match: {
_id: req.user._id
}
},
{
$project: {
password: 0
}
},
{
$lookup: {
from: "blogs",
let: {
userId: "$_id"
},
pipeline: [
{
$match: {
$expr: {
$eq: ["$$userId", "$author"]
}
}
},
{
$lookup: {
from: "comments",
let: {
blogId: "$_id"
},
pipeline: [
{
$match: {
$expr: {
$eq: ["$blog", "$$blogId"]
}
}
}
],
as: "comments"
}
}
],
as: "blogs"
}
}
]);
users[0]
将为您提供与选项 1 相同的结果。
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