Sequalize relationship betwen same model - node.js

Question

I am creating a chat application and trying to create a relationship between User and User through friendship. So far I can create a relationship, but in the end only one user assigned a friend. I'm using Express, sequalize with postgress deployed to heroku. I don't know how to achieve it, any help is appreciated
migration:
`enter code here`await queryInterface.createTable('users', { id: { type: DataTypes.UUID, primaryKey: true, defaultValue: DataTypes.UUIDV4, } }, }); await queryInterface.createTable('friendships', { id: { type: DataTypes.UUID, primaryKey: true, defaultValue: DataTypes.UUIDV4, }, user: { type: DataTypes.UUID, allowNull: false, references: { model: 'users', key: 'id' }, }, friend: { type: DataTypes.UUID, allowNull: false, references: { model: 'users', key: 'id' }, }, status: { type: DataTypes.ENUM('PENDING', 'ACCEPTED', 'DENIED'), allowNull: false, defaultValue: 'PENDING', }, });
friendship model:
Friendship.init(
{
id: {
type: DataTypes.UUID,
primaryKey: true,
defaultValue: DataTypes.UUIDV4,
},
user: {
type: DataTypes.UUID,
allowNull: false,
references: {
model: 'users',
key: 'id',
},
},
friend: {
type: DataTypes.UUID,
allowNull: false,
references: {
model: 'users',
key: 'id',
},
},
status: {
type: DataTypes.ENUM('PENDING', 'ACCEPTED', 'DENIED'),
allowNull: false,
defaultValue: 'PENDING',
},
},
{
sequelize,
underscored: true,
timestamps: false,
modelName: 'friendship',
}
);
associations:
User.belongsToMany(User, { as: 'friends', through: Friendship, foreignKey: 'user',
otherKey: 'friend' });
Friendship.belongsTo(User, { as: 'info', foreignKey: 'friend' });
controller:
export const addFriend = async (req: Request, res: Response) => {
try {
const { friendId } = req.body;
const userId = req.decodedToken?.id;
const friend = await User.findByPk(friendId, {
attributes: { exclude: ['passwordHash'] },
include: [{ model: User, as: 'friends' }],
});
if (friend)
await Friendship.create({
user: userId,
friend: friend.id,
status: 'PENDING',
});
return res.status(200).json({ status: 'success' });
} catch (e) {
res.status(500).json({ error: 'The server cannot create the user' });
console.log(e);
}
};
response:
"users": {
"count": 2,
"rows": [
{
"id": "e7c7ce39-953a-45e7-a892-a5f99554382e",
"email": "admin",
"username": "admin",
"name": null,
"surname": null,
"age": null,
"public": true,
"image": null,
"friends": [
{
"id": "13029ad9-7199-47d5-bd1c-7d939b26150e",
"email": "admin2",
"username": "admin",
"passwordHash": "$2b$10$GajlewYeiGvUOOV08YOzLuedV/8.KJNUeHB4WPKlUFxErj91ljfWq",
"name": null,
"surname": null,
"age": null,
"public": true,
"image": null,
"friendship": {
"id": "a78b9336-f5a6-4153-b3e1-e44dbe1cc7a6",
"user": "e7c7ce39-953a-45e7-a892-a5f99554382e",
"friend": "13029ad9-7199-47d5-bd1c-7d939b26150e",
"status": "PENDING"
}
}
]
},
{
"id": "13029ad9-7199-47d5-bd1c-7d939b26150e",
"email": "admin2",
"username": "admin",
"name": null,
"surname": null,
"age": null,
"public": true,
"image": null,
"friends": []
}
Edit:
I made something like this, it's not perfect, but it's good for me
User.belongsToMany(User, { as: 'friends', through: Friendship, foreignKey: 'user' });
User.belongsToMany(User, { as: 'friend', through: Friendship, foreignKey: 'friend' });

Answer 1

Please consider a many to many relationship.
An user can be a friend of many users.
Many users can be friends of one user.
You may found the how-to implement in the official doc: here.
Basically, use belongsToMany in both associations:
Implementation
The main way to do this in Sequelize is as follows:
const Movie = sequelize.define('Movie', { name: DataTypes.STRING });
const Actor = sequelize.define('Actor', { name: DataTypes.STRING });
Movie.belongsToMany(Actor, { through: 'ActorMovies' });
Actor.belongsToMany(Movie, { through: 'ActorMovies' });