iflrandevu/application/migrations/037_add_timestamp_columns.php

<?php defined('BASEPATH') or exit('No direct script access allowed');

/* ----------------------------------------------------------------------------
 * Easy!Appointments - Open Source Web Scheduler
 *
 * @package     EasyAppointments
 * @author      A.Tselegidis <alextselegidis@gmail.com>
 * @copyright   Copyright (c) 2013 - 2020, Alex Tselegidis
 * @license     http://opensource.org/licenses/GPL-3.0 - GPLv3
 * @link        http://easyappointments.org
 * @since       v1.4.0
 * ---------------------------------------------------------------------------- */

class Migration_Add_timestamp_columns extends EA_Migration {
    /**
     * @var string[]
     */
    protected $tables = [
        'appointments',
        'categories',
        'consents',
        'roles',
        'services',
        'settings',
        'users'
    ];

    /**
     * @var string[]
     */
    protected $columns = [
        'delete_datetime',
        'update_datetime',
        'create_datetime',
    ];

    /**
     * Upgrade method.
     */
    public function up()
    {
        foreach ($this->tables as $table)
        {
            foreach ($this->columns as $column)
            {
                if ( ! $this->db->field_exists($column, $table))
                {
                    $fields = [
                        $column => [
                            'type' => 'DATETIME',
                            'null' => TRUE,
                            'after' => 'id',
                        ]
                    ];

                    $this->dbforge->add_column($table, $fields);
                }
            }
        }
    }

    /**
     * Downgrade method.
     */
    public function down()
    {
        foreach ($this->tables as $table)
        {
            foreach ($this->columns as $column)
            {
                if ($this->db->field_exists($column, $table))
                {
                    $this->dbforge->drop_column($table, $column);
                }
            }
        }
    }
}