More seeder examples needed

[andrewwippler]

I am new to adonisjs (while not necessarily new to MVCs) and I found it difficult to seed a many-to-many relationship. (i.e. it took me over 24 hours to get the answer).

The error I was getting was:

From previous event:
    at Runner.run (/usr/src/app/node_modules/knex/lib/runner.js:34:31)
    at Builder.Target.then (/usr/src/app/node_modules/knex/lib/interface.js:20:43) {
  code: 'ER_BAD_FIELD_ERROR',
  errno: 1054,
  sqlMessage: "Unknown column '__setters__' in 'field list'",
  sqlState: '42S22',
  index: 0,
  sql: "insert into `ill_tags` (`illustration_id`, `tag_id`) values (2, `__setters__` = '$attributes', '$persisted', 'primaryKeyValue', '$originalAttributes', '$relations', '$sideLoaded', '$parent', '$frozen', '$visible', '$hidden', `$attributes` = '[object Object]', `$persisted` = false, `$originalAttributes` = '[object Object]', `$relations` = '[object Object]', `$sideLoaded` = '[object Object]', `$parent` = NULL, `$frozen` = false, `$visible` = 'id', 'name', `$hidden` = NULL)"

I was defining my seeder as the following to get the issue:

const illustrations = await Factory.model('App/Models/Illustration').createMany(5)
const tags = await Factory.model('App/Models/Tag').createMany(10)

await illustrations[0].tags().attach(tags[0])

The solution (to specify id) was found on issue adonisjs/lucid#178 -

await illustrations[0].tags().attach(tags[0].id)

So I propose adding to the seeder documentation the following:

const users = await Factory.model('App/Models/User').createMany(5)
const cars = await Factory.model('App/Models/Car').createMany(10)

// single car
await users[0].cars().attach(cars[0].id)
    
// all cars
const allCars = cars.map(car => car.id);
await users[0].cars().attach(allCars);