One to many relationship in sequelize with MYSQL - mysql

Question

I have two tables:
const attr = {
name: {
type: DataTypes.STRING,
},
};
const Tags = createModel('Tags', attr, {});
and:
const attr = {
tagId: {
type: DataTypes.INTEGER,
references: { model: 'Tags', key: 'id' },
}
}
const Client = createModel('Client', attr, {})
Client.belongsTo(Tag, { foreignKey: 'tagId', as: 'tags' });
and my query is this:
const clientCount = await Client.findAll({
include: [ { model: Tags, as: 'tags' } ],
attributes: { exclude: 'tagId' }
});
and this is my response:
{
"id": 1,
"createdAt": "2020-01-20T00:00:00.000Z",
"updatedAt": "2020-01-22T00:00:00.000Z",
"tags": {
"id": 1,
"name": "New tag",
"createdAt": "2020-01-20T00:00:00.000Z",
"updatedAt": "2020-01-20T00:00:00.000Z"
}
}
but I want my tags to be an array, so I guest I have to define a one to many association, but everything I tried so far failed.
What I want is tags to be an array, where I can add multiple tag objects:
{
"id": 1,
"createdAt": "2020-01-20T00:00:00.000Z",
"updatedAt": "2020-01-22T00:00:00.000Z",
"tags": [
{
"id": 1,
"name": "New tag",
"createdAt": "2020-01-20T00:00:00.000Z",
"updatedAt": "2020-01-20T00:00:00.000Z"
}
]
}

Answer 1

Method1
We need new model as Client_Tag
const attr = {
clientId: {
type: DataTypes.INTEGER,
},
tagId: {
type: DataTypes.INTEGER,
},
};
const Client_Tag = createModel('Client_Tag', attr, {});
Client.belongsToMany(Tag, {
foreignKey: 'clientId',
otherKey: 'tagId',
through: models.Client_Tag,
as: 'tags'
});
const clientCount = await Client.findAll({
include: [ { model: Tags, as: 'tags' } ],
attributes: { exclude: 'tagId' }
});
Method2
const attr = {
name: {
type: DataTypes.STRING,
},
clientId: { // need clientId in tag model, and remove 'tagId' from client model
type: DataTypes.INTEGER,
}
};
const Tags = createModel('Tags', attr, {});
Client.belongsToMany(Tag, { foreignKey: 'tagId', as: 'tags' });