destroying

To destroy a model, simply call the destroy method on the instance.

import User from 'app/models/user'

const user = await User.first()
await user.destroy()

Associations can be destroyed using destroyAssociation:

const place = await Place.first()
await place.destroyAssociation('rooms')
// OR
await place.destroyAssociation('rooms', { and: { name: 'my room' } })

Cascading

Deletion will cascade through associations declared dependent: 'destroy'. If each associated model is decorated with @SoftDelete (see below), then the models corresponding to that association will be soft deleted.

const deco = new Decorators<InstanceType<typeof Place>>()

export default class Place extends ApplicationModel {
  @deco.HasMany('Room', { dependent: 'destroy' })
  public rooms: Room[]
}

await Room.count()
// 3
const place = await Place.first()
await place.associationQuery('rooms').count()
// 3
await place.destroy()
await Room.count()
// 0

@SoftDelete

Soft deletion enables a model to be hidden, by default, from all queries, without actually being deleted from the database. This is useful for providing a "undo" deletion and "trash" functionality.

To activate soft deletion, first create a migration to add a deleted_at column to the database:

yarn psy g:migration add-deleted-at-to-rooms deleted_at:datetime

Then apply the @SoftDelete decorator to the Dream model class:

@SoftDelete()
export default class Place extends ApplicationModel {
  ...
}

NOTE: when using soft deletion, it is recommended that the default foreign key deletion constraint of 'restrict' be used:

  await db.schema
    .createTable('rooms')
    .addColumn('id', 'bigserial', col => col.primaryKey())
    .addColumn('place_id', 'bigint', col => col.references('places.id').onDelete('restrict').notNull())
    .execute()
}

Loading soft deleted models

Soft deleted models can be included in queries by removing all default scopes or specfically the soft delete scope:

await Place.create({ name: 'My Place' })
await Place.count()
// 1
await Place.destroy()
await Place.count()
// 0
await Place.removeAllDefaultScopes().count()
// 1
await Place.removeDefaultScope('dream:SoftDelete').count()
// 1

Deleting @SoftDelete models from the database

A model marked @SoftDelete can be deleted with reallyDestroy. As with

await Place.create({ name: 'My Place' })
await Place.count()
// 1
await Place.reallyDestroy()
await Place.removeAllDefaultScopes().count()
// 0