[v4] How to get array of ids of a relation .with('tags') of belongsToMany?

[leandroaphermes]

I'm doing a fetch to get the tags a user has

waiting for a structure like

[{
  id: 1,
  ....,
  tags: [ 2, 5, 7, ... ]
}] 

// App/HTTP/UserController
  const users = await User.query().with('tags').fetch()

// App/Models/User
  tags(){
    return this.belongsToMany('App/Models/Tag').pivotTable('tag_user')
  }

[leandroaphermes]

I managed to make the query return only the ids of the markers without using relationship in the select

Solution:

// App/HTTP/UserController
await User.query().select([
  "id",
  "name",
  Database.raw(
    `(
        SELECT JSON_ARRAYAGG(tag_user.tag_id) FROM tag_user WHERE tag_user.user_id= user.id
      ) as tag_ids`
  ),
]).fetch()

// App/Models/User
class User {
  getTagIds(value) {
    return value ? JSON.parse(value) : [];
  }
}