Sequelize one to many association - node.js

Question

I am trying to map sequelize one to many association by referring to sequelize documentation but I could not able to find a complete example to get it work.
I have a ClaimType model as follows
const Sequelize = require('sequelize');
module.exports = function (sequelize) {
const ClaimType = sequelize.define('claim_type', {
id: {
type: Sequelize.INTEGER,
autoIncrement: true,
primaryKey: true
},
name: {
type: Sequelize.STRING
}
}, {
timestamps: false,
freezeTableName: true
});
return ClaimType;
};
and MaxClaimAmount
const Sequelize = require('sequelize');
module.exports = function (sequelize) {
const MaxClaimAmount = sequelize.define('max_claim_amount', {
id: {
type: Sequelize.INTEGER,
autoIncrement: true,
primaryKey: true
},
amount: {
type: Sequelize.DECIMAL
},
year: {
type: Sequelize.INTEGER
}
}, {
timestamps: false,
freezeTableName: true
});
return MaxClaimAmount;
};
finally in index.js
const ClaimType = require('./model/claim_type.js')(sequelize);
const MaxClaimAmount = require('./model/max_claim_amount.js')(sequelize);
ClaimType.hasMany(MaxClaimAmount, { as: 'claimAmount' });
sequelize.sync({ force: false }).then(() => {
return sequelize.transaction(function (t) {
return ClaimType.create({
name: 'OPD'
}, { transaction: t }).then(function (claimType) {
// want to know how to associate MaxClaimAmount
});
}).then(function (result) {
sequelize.close();
console.log(result);
}).catch(function (err) {
sequelize.close();
console.log(err);
});
});
ClaimType object is returned from the first part of the transaction and I want to know how to implement the association between ClaimType and MaxClaimAmount?

Answer 1

You make the association in your models.
(Associations: one-to-many in sequelize docs)
const ClaimType = sequelize.define('claim_type', {/* ... */})
const MaxClaimAmount = sequelize.define('max_claim_type', {/* ... */})
ClaimType.hasMany(MaxClaimAmount, {as: 'MaxClaims'})
This will add the attribute claim_typeId or claim_type_id to MaxClaimAmount (you will see the column appear in your table). Instances of ClaimType will get the accessors getMaxClaims and setMaxClaims (so you can set foreign id on table)
The next step would be creating your backend routes and using the accessor instance methods to set a foreign key. The accessor functions are called like so: (instance1).setMaxClaims(instance2)
Instances are returned from queries