sample migration file

20170926205038_create_posts_table.php

<?php namespace App\Database\Migrations;

use CodeIgniter\Database\Migration;

class Migration_create_posts_table extends Migration
{
	public function up()
	{
		$this->forge->addField([
			'id'         => [
				'type'           => 'INT',
				'constraint'     => 5,
				'unsigned'       => true,
				'auto_increment' => true,
			],
			'title'      => [
				'type'       => 'VARCHAR',
				'constraint' => '100',
			],
			'slug'       => [
				'type'       => 'VARCHAR',
				'constraint' => 100,
			],
			'content'    => [
				'type' => 'TEXT',
				'null' => true,
			],

			'created_at' => [
				'type' => 'DATETIME',
			],
			'status'     => [
				'type'       => 'VARCHAR',
				'constraint' => '10',
			],
		]);
				$this->forge->addKey('id', true);
				$this->forge->createTable('posts');
	}

	public function down()
	{
		$this->forge->dropTable('posts');
	}
}