Sequelize Model Relationships - node.js

Question

I have 2 models and what I am trying to do is when a match is created, it will automatically create a match report. here is the code:
Match.js
const Sequelize = require('sequelize');
const db = require('../config/database');
const Match = db.define('matches',{
id: {
type: Sequelize.INTEGER(10).UNSIGNED,
autoIncrement: true,
primaryKey: true
},
type: {
type: Sequelize.STRING,
defaultValue: 'main' //match type either Main or Sub
},
game_grp: {
type: Sequelize.SMALLINT(6),
defaultValue: null // belongs to main match side bet.
},
sub_type: {
type: Sequelize.STRING,
defaultValue: null //values: (other = 1stBlood,F10k), (main = MatchWinner), (handicap = Match Handicap)
},
name: {
type: Sequelize.STRING,
defaultValue: null
},
league_id: {
type: Sequelize.INTEGER,
allowNull: false,
references: {
model: 'League', //leagues has many matches
key: 'id'
}
},
},
);
Match.associate = models => {
Match.hasMany(models.MatchReport, {
foreignKey: 'id'
});
};
module.exports = Match;
MatchReport.js
const Sequelize = require('sequelize');
const db = require('../config/database');
const MatchReport = db.define('match_reports',
{
id: {
type: Sequelize.INTEGER.UNSIGNED,
autoIncrement: true,
primaryKey: true,
references: {
model: 'Match', //MatchReport's ID belongs to matches'
key: 'id'
}
},
league_id: {
type: Sequelize.INTEGER,
defaultValue: 0,
references: {
model: 'Match',
key: 'league_id'
}
},
name: {
type: Sequelize.STRING,
defaultValue: null
},
status: {
type: Sequelize.STRING,
defaultValue: null //ongoing,draw,cancelled,open
},
);
module.exports = MatchReport;
I'm new to node.js and sequelize.js model relationships so it's quite hard to understand some of the documentation's details.
Any ideas on how to deal with this? TYIA

Answer 1

First, you have a problem with MatchReport definition:
It needs to have its own id as PK and not as FQ.
MatchReport.league_id is referencing to Match.league_id, so if you'll point to a Match instance it's redundant, right? So, let's point to Match instance instead.
Define your MatchReport as follows:
const Sequelize = require('sequelize');
const db = require('../config/database');
const MatchReport = db.define('match_reports',
{
id: {
type: Sequelize.INTEGER.UNSIGNED,
autoIncrement: true,
primaryKey: true,
},
match_id: {
type: Sequelize.INTEGER(10).UNSIGNED,
references: {
model: 'Match',
key: 'id'
}
},
name: {
type: Sequelize.STRING,
defaultValue: null
},
status: {
type: Sequelize.STRING,
defaultValue: null //ongoing,draw,cancelled,open
},
);
module.exports = MatchReport;
Now, there are some options to create MatchReport instance when a Match is created.
1) Put the logic inside a function that creates a match.
async function createMatch(match) {
// match is the object you want to insert.
var newMatch = await Match.create(data);
var newMatchReport = await MatchReport.create({
match_id: newMatch.id,
name: ...,
status: ...., //
});
}
2) Use the include option of sequelize.
async function createMatch(match) {
// match is the object you want to insert.
var newMatch = await Match.create(data, {
include: [{ model: MatchReport}]
});
}
Pay attention to the following points as well:
1) When creating an instance of a model the whole instance returns and not only the data. The data itself could be found under dataValues object.
2) You need to apply the associations between the models as follows:
In your Match model:
let MatchReport = require('./MatchReport');
Match.hasOne(MatchReport);
In your MatchReport model:
let Match = require('./Match');
MatchReport.belongsTo(Match);