Adonis js 迁移时删除列：回滚

Question

I am using adonis js to make a website. I need to add certain columns to an existing table via migration and also drop those columns when I run "adonis migration:rollback". How do I write the migration down() function?

The Code that I mention below for adonis make:migration medicines --action=select

'use strict'

/** @type {import('@adonisjs/lucid/src/Schema')} */
const Schema = use('Schema')

class MedicinesSchema extends Schema {
  up () {
    this.alter('medicines', (table) => {
      // alter table
      table.boolean('front_page');
      table.integer( 'brand_id' ).nullable();
      table.integer('offer_id').nullable();

    })
  }

  down () {
    this.table('medicines', (table) => {
      // reverse alternations
      // HOW DO I WRITE THE REVERSALS HERE ?
    })
  }
}

module.exports = MedicinesSchema

THANKS IN ADVANCE

Answer 1

You can use dropColumn()

Official doc example: https://knexjs.org/#Schema-table

knex.schema.table('users', function (table) {
  table.dropColumn('name');
  table.string('first_name');
  table.string('last_name');
})

Outputs:

alter table `users` add `first_name` varchar(255), add `last_name` varchar(255);
alter table `users` drop `name`

---

Adonis version:

down () {
   this.table('medicines', (table) => {
      table.dropColumn('myColumn');
   })
}

---

AdonisJS use Knex for database query