Schema Helpers

Adonis.js provides a rich set of schema helpers via its SchemaBuilder API to make defining database tables intuitive and expressive. These helpers abstract common SQL types and constraints, making your migrations cleaner and more consistent.

Here’s a breakdown of some commonly used schema helpers:

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📌 Column Types

Helper	Description
table.increments()	Auto-incrementing primary key (usually id)
table.uuid('id')	UUID column, great for distributed systems
table.string('name', [length])	VARCHAR column, default length is 255
table.text('description')	TEXT column for longer strings
table.integer('age')	Integer column
table.bigInteger('views')	For large integer values
table.float('price')	Floating-point number
table.decimal('amount', precision, scale)	Precise decimal (e.g., money)
table.boolean('is_active')	Boolean column
table.date('published_at')	Date only
table.dateTime('created_at')	Date and time
table.timestamp('updated_at')	Timestamp with timezone
table.enum('status', ['pending', 'approved', 'rejected'])	Enum column

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🧷 Constraints & Modifiers

Helper	Description
table.primary(['id'])	Set primary key
table.unique(['email'])	Unique constraint
table.index(['name'])	Add index
table.foreign('user_id').references('id').inTable('users')	Foreign key
table.notNullable()	Disallow null values
table.nullable()	Allow null values
table.defaultTo(value)	Set default value

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🕒 Timestamps & Soft Deletes

• table.timestamps()
  Adds created_at and updated_at columns.

• table.timestamp('deleted_at').nullable()
  Used for soft deletes (marking records as deleted without removing them).

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🧰 Other Useful Helpers

Helper	Description
table.json('metadata')	Store JSON data
table.jsonb('settings')	JSONB (PostgreSQL only)
table.binary('file_data')	Binary data
table.specificType('column', 'custom_type')	Define custom SQL type

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Example Migration Using Helpers

import BaseSchema from '@ioc:Adonis/Lucid/Schema'

export default class extends BaseSchema {
  public async up () {
    this.schema.createTable('products', (table) => {
      table.increments('id')
      table.string('name').notNullable()
      table.decimal('price', 10, 2).defaultTo(0.00)
      table.enum('status', ['active', 'inactive']).defaultTo('active')
      table.timestamps()
    })
  }

  public async down () {
    this.schema.dropTable('products')
  }
}