如何用另一个集合moongoose查找子查询文档
如何用另一个集合moongoose查找子查询文档
提问于 2020-01-06 21:24:15
我需要加入用户集合两次，因为同一用户将发布产品和购买的用户详细信息作为子文档。
产品架构：
{
product_title: String,
product_desc: String,
Product_purchased:[
{
userid: mongoose.Schema.ObjectId,
purchased_date: Date
}]
posteduserId: mongoose.Schema.ObjectId
}用户架构：
{
_id: userId,
name: String,
Pic: String
}示例文档：
[
{
"product_title":"title",
"product_desc":"desc",
"Product_purchased":[
{
"userid":"5d4hvh7duc7c7c8d9scbe",
"name":"name",
"Pic":"url",
"purchased_date":"Date"
},
{
"userid":"5d4hvh7duc7c7c8d9scbe",
"name":"name",
"Pic":"url",
"puchased_date":"Date"
}
],
"posteduserId": "5d4hvh7duc7c7c8d9scbe",
"userid": "5d4hvh7duc7c7c8d9scbe",
"name": "name",
"pic": "url",
}
]将同一用户表与发布的userid和购买的userIds的子数组连接起来。
请告诉我如何破解这个，提前谢谢。
回答 1
Stack Overflow用户
回答已采纳
发布于 2020-01-06 22:12:03
首先，您需要像这样修改Product模式，使其包含ref字段：
const mongoose = require("mongoose");
const ProductSchema = new mongoose.Schema({
product_title: String,
product_desc: String,
Product_purchased: [
{
userid: {
type: mongoose.Schema.ObjectId,
ref: "User"
},
purchased_date: Date
}
],
posteduserId: {
type: mongoose.Schema.ObjectId,
ref: "User"
}
});
module.exports = mongoose.model("Product", ProductSchema);我这样设置用户模型：
const mongoose = require("mongoose");
const UserSchema = new mongoose.Schema({
name: String,
Pic: String
});
module.exports = mongoose.model("User", UserSchema);ref User值必须与用户模型中的模型名称User匹配。
然后，您需要像这样填充两次：
router.get("/products", async (req, res) => {
const result = await Product.find({})
.populate("Product_purchased.userid")
.populate("posteduserId");
res.send(result);
});假设你有这3个用户：
{
"_id": "5e133deb71e32b6a68478ab4",
"name": "user1 name",
"Pic": "user1 pic",
"__v": 0
},
{
"_id": "5e133df871e32b6a68478ab5",
"name": "user2 name",
"Pic": "user2 pic",
"__v": 0
},
{
"_id": "5e133e0271e32b6a68478ab6",
"name": "user3 name",
"Pic": "user3 pic",
"__v": 0
}和这个产品：
{
"_id": "5e133e9271e32b6a68478ab8",
"product_title": "product1 title",
"product_desc": "product1 description",
"Product_purchased": [
{
"purchased_date": "2020-01-06T14:02:14.029Z",
"_id": "5e133e9271e32b6a68478aba",
"userid": "5e133df871e32b6a68478ab5"
},
{
"purchased_date": "2020-01-06T14:02:14.029Z",
"_id": "5e133e9271e32b6a68478ab9",
"userid": "5e133e0271e32b6a68478ab6"
}
],
"posteduserId": "5e133deb71e32b6a68478ab4",
"__v": 0
}结果将是：
[
{
"_id": "5e133e9271e32b6a68478ab8",
"product_title": "product1 title",
"product_desc": "product1 description",
"Product_purchased": [
{
"purchased_date": "2020-01-06T14:02:14.029Z",
"_id": "5e133e9271e32b6a68478aba",
"userid": {
"_id": "5e133df871e32b6a68478ab5",
"name": "user2 name",
"Pic": "user2 pic",
"__v": 0
}
},
{
"purchased_date": "2020-01-06T14:02:14.029Z",
"_id": "5e133e9271e32b6a68478ab9",
"userid": {
"_id": "5e133e0271e32b6a68478ab6",
"name": "user3 name",
"Pic": "user3 pic",
"__v": 0
}
}
],
"posteduserId": {
"_id": "5e133deb71e32b6a68478ab4",
"name": "user1 name",
"Pic": "user1 pic",
"__v": 0
},
"__v": 0
}
]页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/59612935
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