CODEWITHSUNDEEP
sequelize.jshas-and-belongs-to-many
Luiz Henrique Martins Lins Rol
Luiz Henrique Martins Lins Rol

Reputation: 2599

Sequelize query belongstomany not including child attributes

I´m new to sequelize and trying to determine how to perform a query on a belongstomany relationship, where I need to check for the existence of the child relationship but I don´t want to bring any of its fields.

  Project.belongsToMany(models.User, {
        through: 'userproject', as: 'links', foreignKey: 'project_id', otherKey: 'user_id'
    });

My attempt:

  const linkedProjects = this.model.findAll({
        attributes: ['Project.*'],
        include: [{
            model: models.User,
            as: 'links',
            where: {
                userid: user.sub
            }
        }]
    });

However this stil brings me the projected links data, which is useless for me except for the where part.

What´s the best way to accomplish that without a "raw query" ? I´m looking for, basically:

select p.* from project p 
inner join userproject up on p.project_id = up.project_id 
inner join user u on up.user_id = u.id
where u.userid = 'xxx'

Upvotes: 0

Views: 2448

Answers (3)

Bass
Bass

Reputation: 51

In a BelongsToMany fetching with sequelize's finders (findAll, findOne...), you can use the

through: {
  attributes: ['created_at']
}

For specify those fields to show in the child record.

Docs: https://sequelize.org/docs/v6/advanced-association-concepts/advanced-many-to-many/#specifying-attributes-from-the-through-table

Upvotes: 0

chettyharish
chettyharish

Reputation: 1734

Re-iterating for marking it as a solution.

The solution is to add attributes: [] to retrieve no columns in the sequelize operation. The attributes field is an array containing column names which have to be retrieved while executing the sequelize operation.

  const linkedProjects = this.model.findAll({
        attributes: ['Project.*'],
        include: [{
            model: models.User,
            as: 'links',
            attributes: [],
            where: {
                userid: user.sub
            }
        }]
    });

Upvotes: 1

Vivek Doshi
Vivek Doshi

Reputation: 58523

Instead of this :

attributes: ['Project.*'], // this will load only fields from project table

Use 

this.model.findAll({
    attributes: ['id','title',...], // all the attributes from project table
    include: [{
        model: models.User,
        attributes: ['id','project_id' ,], // all the attributes from user table
        as: 'links',
        where: {
            userid: user.sub
        }
    }]
});

//OR 

// remove attributes from all
this.model.findAll({
    include: [{
        model: models.User,
        as: 'links',
        where: {
            userid: user.sub
        }
    }]
});

Upvotes: 0

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