Sequelize findAll and Join table - mysql

Question

I want to do a simple chat app and my tables are like this (I don't know if it's the proper way to implement it):
var User = sequelize.define('User', {
userName: DataTypes.STRING,
email: DataTypes.STRING,
password: DataTypes.STRING
}, {
classMethods: {
associate: function(models) {
User.hasMany(models.Friend);
}
}
Friends:
var Friend = sequelize.define('Friend', {
realId: DataTypes.INTEGER,
invitStatus: DataTypes.STRING
}, {
classMethods: {
associate: function(models) {
Friend.hasMany(models.Message);
}
Messages:
var Message = sequelize.define('Message', {
text: DataTypes.TEXT,
sentBy: DataTypes.INTEGER
}, {
classMethods: {
associate: function(models) {
}
This is my current query:
models.User.findAll({
where: {
id: req.payload.userId
},
include: [{
model: models.Friend,
include: [{
model: models.Message,
order: [['createdAt', 'DESC']],
limit: 1
}]
}]
}).then(function(result) {
reply(result).code(200);
})
}
Everything is working fine, except that I want to tell sequelize to get the Friend data from the User table with the realId from the Friend table.
Should I use the keyword "through"? I didn't get exactly how it works even though I read the docs multiple times. I'm a beginner in SQL.
Thanks for your help.
Edit: My current output is:
{
"id": 2,
"userName": "user2",
"email": "user2#example.com",
"password": "123456",
"createdAt": "2016-05-26T16:28:02.000Z",
"updatedAt": "2016-05-26T16:28:13.000Z",
"Friends": [
{
"id": 1,
"realId": 1,
"invitStatus": "accepted",
"createdAt": "2016-05-26T16:30:15.000Z",
"updatedAt": "2016-05-26T16:30:15.000Z",
"UserId": 2,
"Messages": [
{
"id": 18,
"text": "ok",
"sentBy": 1,
"createdAt": "2016-05-26T16:59:36.000Z",
"updatedAt": "2016-05-26T16:59:36.000Z",
"FriendId": 1
}
]
}
What I want is to add the value "userName", "email" and "password" to the Friends array by getting it from the User table with the "Friend.realId = User.id.

Answer 1

I'm not sure to clearly understand your problem. I assume that Friends is linked to User by realId so you shouldn't have a Friends model but only one User model.
If this answer can help anyone, in this case you should probably use self-association.
You can achive self-association between User and User (as friend) with something like
User.belongsToMany(models.User, { as: 'friends', foreignKey: 'userId', through: 'User_Friends' });
And if your User_Friends model need additional attributes you can specified them like below, else this join table will be automatically created.
var User_Friends = sequelize.define('User_Friends', {
// ...
invitStatus: DataTypes.STRING
// ...
}