How do I run CodeIgniter migrations?

You can also run some version for down or up migrations:

if(!defined('BASEPATH')) exit('No direct script access allowed');
class Migrate extends CI_Controller{

    public function __construct()
    {
        parent::__construct();
        $this->load->library('migration');
    }

     public function version($version)
     {
         if($this->input->is_cli_request())
         {
            $migration = $this->migration->version($version);
            if(!$migration)
            {
                echo $this->migration->error_string();
            }
            else
            {
                echo 'Migration(s) done'.PHP_EOL;
            }
        }
        else
        {
            show_error('You don\'t have permission for this action');;
        }
     }
 }

For CLI run this command php index.php migrate version 5, where 5 is version of migration. If version is more of current migration - migration up, else - down to entered version.

Using these pages as references: Running via the CLI and Migration Class you're able to restrict access to your migration controller to command line with something along these lines (application/controllers/migrate.php):

<?php  if ( ! defined('BASEPATH')) exit("No direct script access allowed");

class Migrate extends CI_Controller {

  public function __construct()
  {
    parent::__construct();

    $this->input->is_cli_request()
      or exit("Execute via command line: php index.php migrate");

    $this->load->library('migration');
  }

  public function index()
  {
    if(!$this->migration->latest())
    {
      show_error($this->migration->error_string());
    }
  }
}

then to execute your latest migration, cd into the root of your project directory and run:

php index.php migrate

but when you attempt to access via webserver example.com/migrate you will see the text in the script above.

I am not sure this is the right way to do it, But It works for me.

I created a controller named migrate (controllers/migrate.php).

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

class Migrate extends CI_Controller{

    public function index($version){
        $this->load->library("migration");

      if(!$this->migration->version($version)){
          show_error($this->migration->error_string());
      }   
    }
}

Then from browser I will call this url to execute index action in migrate controller
Eg : http://localhost/index.php/migrate/index/1