How to add a field from associated model using Sequelize?

Question

I'm making a web API using Node, Express, and Sequelize. I have models Users and Teams (shown below). Users has a teamId that references Teams.id, and there is an association between the two to reflect that.

User definition

const User = sequelize.define('User', {
    id: {
        autoIncrement: true,
        type: DataTypes.INTEGER,
        allowNull: false,
        primaryKey: true
    },
    displayName: {
        type: DataTypes.STRING,
        allowNull: false
    },
    teamId: {
        type: DataTypes.INTEGER,
        allowNull: false,
        references: {
            model: 'Team',
            key: 'id'
        }
    }
}

Team definition

const Team = sequelize.define('Team', {
    id: {
        autoIncrement: true,
        type: DataTypes.INTEGER,
        allowNull: false,
        primaryKey: true
    },
    name: {
        type: DataTypes.STRING,
        allowNull: false
    }
}

Association

User.belongsTo(Team, { as: 'team', foreignKey: 'teamId' });

Query

Users.findAll({
    include: [
        {
            model: Team,
            as: 'team'
        }
    ]
});

As expected, this returns a list of User objects, with the added "team" property the respective Team objects embedded like so:

[
    {
        "id": 1,
        "displayName": "John Smith",
        "teamId": 1,
        "team": {
            "id": 1,
            "name": "My Awesome Team"
        }
    }
]

My goal is to return User objects, but instead of embedding the entire Team object under the team property, I'd like to add just the name of the team as the value of the property, like this:

[
    {
        "id": 1,
        "displayName": "John Smith",
        "teamId": 1,
        "team": "My Awesome Team"
    }
]

Is there a way to accomplish this with Sequelize?

score 1 · Answer 1 · answered Dec 08 '20 at 20:22

Well, through typing up my question I thought of better ways to search for the answer, and I think I found one right off the bat...

I found this StackOverflow question where the asker was doing what I am trying to do.

The solution is to use attributes.include and Sequelize.col() to include the attribute I want, and in my include options, use attributes: [] to hide the Team objects.

Going off the examples I included in the original post, this is what works for me, giving me nearly the exact output I wanted:

Users.findAll({
    attributes:{
        include: [[Sequelize.col(team.name), 'teamName']]
    }
    include: [
        {
            model: Team,
            as: 'team',
            attributes: []
        }
    ]
});

Output

[
    {
        "id": 1,
        "displayName": "John Smith",
        "teamId": 1,
        "teamName": "My Awesome Team"
    }
]

Since the association uses the alias "team", I had to name my property something different, and went with "teamName" which is perfectly fine and probably preferable since it is more descriptive.

How to add a field from associated model using Sequelize?

1 Answers1