One to One Relationship MongoDB (Linking)

Learn MongoDB by short way

Tools

• Docker
• MongoDB Image from Docker Hub
• mongosh

One to One Relationship (Linking)

Schema

author
 - _id (auto generate)
 - name
 - age
 
 address
 - _id
 - user_id (fk)
 - street
 - city

Mongo SH

Connection:

$ mongosh mongodb://docker:[email protected]:55000

Pipeline:

show dbs;

use test;
db.author.drop();
db.address.drop();
db.createCollection('author');
db.createCollection('address');

/* Preparing data  for author */
db.author.insertMany([{ name:String('Tran Van A'), age:NumberInt(20)},{ name:String('Nguyen Van B'), age:NumberInt(30)},{ name:String('Le Thi C'), age:NumberInt(40)}]);

db.address.insertOne({
        street:'Hai Bà Trưng',
        city:'HCM'});

db.author.find({}).pretty();
db.address.find({}).pretty();

db.author.findOne({ name:'Tran Van A'});// Get all field with name 
db.author.findOne({ name:'Tran Van A'},{_id:true});// Get both Key and Value
db.author.findOne({ name:'Tran Van A'},{_id:true})._id;// Get only Value

// Add addresss for Auth name Tran Van A
db.address.insertOne({
        user_id: db.author.findOne({ name:'Tran Van A'},{_id:true})._id,
        street:'Nguyen Hue',
        city:'HCM'});

db.address.find({}).pretty();

// Update Address without Author

db.address.insertOne({
        street:'Hai Bà Trưng',
        city:'HCM'});

db.address.find({}).pretty();// Update Address to Author with Name
db.address.updateOne({
        street:'Hai Bà Trưng'},{
    $set:{
        user_id: db.author.findOne({ name:'Nguyen Van B'},{_id:true})._id
    }});

db.address.find({}).pretty();// From Address get User
db.address.aggregate([{
        $lookup:{
                from:"author",// Author table
                localField:"user_id",// Local Field from Address
                foreignField:"_id",// Author table, Col _idas:"users_list"// Descrise User Detail}}]).pretty();// From author get the address
db.author.aggregate([{
    $lookup:{
            from:"address",// Address table
            localField:"_id",// Local Field from Address
            foreignField:"user_id",// Author table, Col _idas:"address_info"// Descrise User Detail}}]);

db.author.find({});
db.address.find({});

Tham khảo
https://github.com/Ducmy/learn-mongodb-by-line/blob/main/README.md