我如何在 adonis 中使用 Lucid 模型/查询生成器进行此查询？

Question

I need to make a query that return all book_unit_questions of one Book.

So, i have the Book.Id.

I'm trying something like:

SELECT BO.id,
BUQ.description
FROM book_unit_question BUQ 
JOIN book_unit BU
ON(BUQ.book_unit_id = BU.book_id)
INNER JOIN Books BO
ON(BU.book_id = 1)

But this way is returning id from other books, and i was expected some the id 1:

My migrations files:

class BookSchema extends Schema {
  up () {
    this.create('books', (table) => {
      table.increments()
      table.string('code').notNullable().unique()
      table.string('description')
      table.string('authors')
      table.boolean('status').defaultTo(false)
      table.integer('user_id').references('id').inTable('users')
      table.timestamps()
    })
  }

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.integer('sequence').notNullable()
      table.string('description')
      table.integer('qt_question')
      table.boolean('status').defaultTo(false)
      table.integer('user_id').references('id').inTable('users')
      table.timestamps()
      table.unique(['unit', 'sequence', 'book_id'])
    })
  }

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()
    })
  }

Answer 1

Edited: This version does not use manyThrough()

Controller:

    const BookUnit = use('App/Models/BookUnit')
    const Question = use('App/Models/BookUnitQuestion')

    const bIds = await BookUnit.query().where('book_id', 1).ids() //Get all bookUnit ids

    const questions = await Question.query().whereIn('book_unit_id', bIds).fetch()

    return questions

Paginate:

const questions = await Question.query().whereIn('book_unit_id', bIds).paginate(2, 2)

Migration files:

this.create('books', (table) => {
      table.increments()
      table.string('code').notNullable()
      table.string('description').notNullable()
      table.timestamps()
})

this.create('book_units', (table) => {
      table.increments()
      table.integer('book_id').unsigned().references('id').inTable('books')
      table.integer('unit')
      table.timestamps()
})

this.create('book_unit_questions', (table) => {
      table.increments()
      table.integer('book_unit_id').unsigned().references('id').inTable('book_units')
      table.integer('description')
      table.timestamps()
})

Don't hesitate if you have any questions

Answer 2

After some tentatives, this code works for my purpose:

 async show(request){
        const bookQuestions = await BookUnitQuestion
                                    .query()
                                    .with('book_unit')
                                    .with('user')
                                    .with('book', (builder) => {
                                        builder.where('id', request.params.id)
                                    })
                                    .paginate()

    return bookQuestions

}