需要建议使用 mongoose 在 mongodb 中设计数据库 [英] Need advice to design database in mongodb with mongoose
问题描述
我有 2 个集合:Hospital 和 Patient.本月患者在A医院检查，但下个月该患者在B医院检查.那么在更新患者信息时，如何保存患者已经在A医院检查的患者历史?请给我一个建议?谢谢
I have 2 collections: Hospital and Patient. This month the patient is examination at hospital A, But next month, this patient is examination at hospital B. So when updating patient information, how to save patient's history that patient is already examination at hospital A? Please give me an advice? Thanks
推荐答案
为此您需要有一个单独的考试集合.(就像关系数据库中的中间(关联)表.)
You need to have a separate examination collection for this. (It is like the intermediate (associative) table in relational databases.)
解决此问题的一种方法是使用虚拟填充.使用虚拟填充，我们不需要保留对考试的引用，这将在添加、更新或删除考试时简化事情.因为只有考试集合需要更新.
One way to solve this is using virtual populate. With virtual populate we don't need to keep references to the examinations, which will simplify things when an examination is added, updated or deleted. Because only the examinations collection will need to be updated.
患者.js
const mongoose = require("mongoose");
const patientSchema = new mongoose.Schema(
{
name: String
},
{
toJSON: { virtuals: true }
}
);
// Virtual populate
patientSchema.virtual("examinations", {
ref: "Examination",
foreignField: "patientId",
localField: "_id"
});
module.exports = mongoose.model("Patient", patientSchema);
hospital.js
hospital.js
const mongoose = require("mongoose");
const hospitalSchema = new mongoose.Schema(
{
name: String
},
{
toJSON: { virtuals: true }
}
);
// Virtual populate
hospitalSchema.virtual("examinations", {
ref: "Examination",
foreignField: "hospitalId",
localField: "_id"
});
module.exports = mongoose.model("Hospital", hospitalSchema);
考试.js
const mongoose = require("mongoose");
const examinationSchema = new mongoose.Schema({
when: {
type: Date,
default: Date.now()
},
patientId: {
type: mongoose.Schema.Types.ObjectId,
ref: "Patient"
},
hospitalId: {
type: mongoose.Schema.Types.ObjectId,
ref: "Hospital"
}
});
module.exports = mongoose.model("Examination", examinationSchema);
如您所见，我们的患者和医院模式非常干净，没有任何检查参考.
As you see our patient and hospital schemas are very clean without any examination reference.
让我们有这些现有的患者.
Let's have these existing patients.
{
"_id" : ObjectId("5e0f86d0ea3eb831a4845064"),
"name" : "Patient 1",
"__v" : NumberInt(0)
},
{
"_id" : ObjectId("5e0f86dbea3eb831a4845065"),
"name" : "Patient 2",
"__v" : NumberInt(0)
}
让我们拥有这些现有的医院.
Let's have these existing hospitals.
{
"_id" : ObjectId("5e0f86feea3eb831a4845066"),
"name" : "Hospital 1",
"__v" : NumberInt(0)
},
{
"_id" : ObjectId("5e0f8705ea3eb831a4845067"),
"name" : "Hospital 2",
"__v" : NumberInt(0)
}
让我们看看这些现有的考试.
Let's have these existing examinations.
/* Patient 1 - Hospital 1 */
{
"when": "2020-01-03T18:27:12.997Z",
"_id": "5e0f878346e50d41d846d482",
"patientId": "5e0f86d0ea3eb831a4845064",
"hospitalId": "5e0f86feea3eb831a4845066",
"__v": 0
},
/* Patient 1 - Hospital 1 */
{
"when": "2020-01-03T18:27:12.997Z",
"_id": "5e0f87a646e50d41d846d483",
"patientId": "5e0f86d0ea3eb831a4845064",
"hospitalId": "5e0f86feea3eb831a4845066",
"__v": 0
},
/* Patient 1 - Hospital 2*/
{
"when": "2020-01-03T18:27:12.997Z",
"_id": "5e0f87c446e50d41d846d484",
"patientId": "5e0f86d0ea3eb831a4845064",
"hospitalId": "5e0f8705ea3eb831a4845067",
"__v": 0
},
/* Patient 2 - Hospital 1 */
{
"when": "2020-01-03T18:27:12.997Z",
"_id": "5e0f87e046e50d41d846d485",
"patientId": "5e0f86dbea3eb831a4845065",
"hospitalId": "5e0f86feea3eb831a4845066",
"__v": 0
}
现在如果我们想获取患者的信息和他/她的检查，我们可以使用以下代码:
Now if we want to get the info of a patient and his/her examinations we can use the following code:
app.get("/patients/:id", async (req, res) => {
const result = await Patient.findById(req.params.id).populate("examinations");
res.send(result);
});
结果是这样的:
{
"_id": "5e0f86d0ea3eb831a4845064",
"name": "Patient 1",
"__v": 0,
"examinations": [
{
"when": "2020-01-03T18:27:12.997Z",
"_id": "5e0f878346e50d41d846d482",
"patientId": "5e0f86d0ea3eb831a4845064",
"hospitalId": "5e0f86feea3eb831a4845066",
"__v": 0
},
{
"when": "2020-01-03T18:27:12.997Z",
"_id": "5e0f87a646e50d41d846d483",
"patientId": "5e0f86d0ea3eb831a4845064",
"hospitalId": "5e0f86feea3eb831a4845066",
"__v": 0
},
{
"when": "2020-01-03T18:27:12.997Z",
"_id": "5e0f87c446e50d41d846d484",
"patientId": "5e0f86d0ea3eb831a4845064",
"hospitalId": "5e0f8705ea3eb831a4845067",
"__v": 0
}
],
"id": "5e0f86d0ea3eb831a4845064"
}
我们甚至可以像这样用内部填充物填充医院:
We can even populate the hospital like this with an inner populate:
app.get("/patients/:id", async (req, res) => {
const result = await Patient.findById(req.params.id).populate({
path: "examinations",
populate: {
path: "hospitalId"
}
});
res.send(result);
});
结果将包含医院信息:
{
"_id": "5e0f86d0ea3eb831a4845064",
"name": "Patient 1",
"__v": 0,
"examinations": [
{
"when": "2020-01-03T18:27:12.997Z",
"_id": "5e0f878346e50d41d846d482",
"patientId": "5e0f86d0ea3eb831a4845064",
"hospitalId": {
"_id": "5e0f86feea3eb831a4845066",
"name": "Hospital 1",
"__v": 0,
"id": "5e0f86feea3eb831a4845066"
},
"__v": 0
},
{
"when": "2020-01-03T18:27:12.997Z",
"_id": "5e0f87a646e50d41d846d483",
"patientId": "5e0f86d0ea3eb831a4845064",
"hospitalId": {
"_id": "5e0f86feea3eb831a4845066",
"name": "Hospital 1",
"__v": 0,
"id": "5e0f86feea3eb831a4845066"
},
"__v": 0
},
{
"when": "2020-01-03T18:27:12.997Z",
"_id": "5e0f87c446e50d41d846d484",
"patientId": "5e0f86d0ea3eb831a4845064",
"hospitalId": {
"_id": "5e0f8705ea3eb831a4845067",
"name": "Hospital 2",
"__v": 0,
"id": "5e0f8705ea3eb831a4845067"
},
"__v": 0
}
],
"id": "5e0f86d0ea3eb831a4845064"
}
现在有了这些知识，您可以自己从医院方面实施检索操作.
Now with this knowledge you can yourself implement the retrieve operations from the hospital side.
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