I can’t get a relationship going Lucido on Adonis

Question

I have the following schema:

Book:

class BookSchema extends Schema {
  up () {
    this.create('books', (table) => {
      table.increments()
      table.string('description')
      table.timestamps()
    })
  }

Bookunit:

class BookUnitSchema extends Schema {
  up () {
    this.create('book_unit', (table) => {
      table.increments()
      table.integer('book_id').references('id').inTable('books').notNullable()
      table.integer('unit').notNullable()
      table.string('description')
      table.integer('user_id').references('id').inTable('users')
      table.timestamps()
      table.unique(['unit', 'sequence', 'book_id'])
    })
  }

Bookunitquestion

class BookUnitQuestionSchema extends Schema {
      up () {
        this.create('book_unit_question', (table) => {
          table.increments()
          table.integer('book_unit_id').references('id').inTable('book_unit')
          table.string('question_form')
          table.string('option_form')
          table.string('type_answer')
          table.string('description')
          table.string('correct_answer_description')
          table.integer('correct_answer_description_id')
          table.text('image_sound')
          table.boolean('status').defaultTo(false)
          table.integer('user_id').references('id').inTable('users')
          table.timestamps()
        })
      }

I need to perform a query that will return me all the questions of a given book. I tried it that way:

const Book = use('App/Models/Book')

const book = await Book.find(2) //Get book from id
await book.load('book_unit_questions') // Load book_unit_questions
const questions = book.getRelated('book_unit_questions') // Return questions
return questions

Then I have the following json result:

[ {"id":1,"book_unit_id":2,"description":null,"created_at":null,"updated_at":null},
       {"id":2,"book_unit_id":5,"description":454,"created_at":null,"updated_at":null}
    ]

However, I need more information about book_unit_id, such as his Description.

I already have the book_unit_id being returned, as I can add more fields in my query?

My Book Models:

user () {
    return this.belongsTo('App/Models/User')
        .select('id', 'username')
}

book_units(){
    return this.hasMany('App/Models/BookUnit')
}

book_unit_questions() {
    return this.manyThrough('App/Models/BookUnit', 'book_unit_questions')
}

My Bookunit Models:

book_unit_questions() {
    return this.hasMany('App/Models/BookUnitQuestion')
}

book () {
    return this.belongsTo('App/Models/Book')
    .select('id', 'description as descricaounidade')
}


user () {
    return this.belongsTo('App/Models/User')
        .select('id', 'username')
}

My bookUnit Question models:

static get table () {
    return 'book_unit_question'
}

user () {
    return this.belongsTo('App/Models/User')
        .select('id', 'username')
}

book_units(){
    return this.belongsTo('App/Models/BookUnitQuestion')
}

books () {
    return this.manyThrough('App/Models/Book', 'book_unit_questions', 'id', 'book_unit_id')
}