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Upgrade Migrations

Documentation

What has been changed

  • First of all, the sequential naming (001_create_users, 002_create_posts) of migrations is no longer supported. Version 4 of CodeIgniter only supports the timestamp scheme (20121031100537_create_users, 20121031500638_create_posts). If you have used sequential naming, you have to rename each migration file.
  • The migration table definition was changed. If you upgrade from CI3 to CI4 and use the same database, you need to upgrade the migration table definition and its data.
  • The migration procedure has also been changed. You can now migrate the database with a simple CLI command:
php spark migrate

Upgrade Guide

  1. If your v3 project uses sequential migration names, you have to change those to timestamp names.
  2. You have to move all migration files to the new folder app/Database/Migrations.
  3. Remove the line defined('BASEPATH') OR exit('No direct script access allowed'); if it exists.
  4. Add this line just after the opening php tag: namespace App\Database\Migrations;.
  5. Below the namespace App\Database\Migrations; line add this line: use CodeIgniter\Database\Migration;
  6. Replace extends CI_Migration with extends Migration.
  7. The method names within the Forge class have been changed to use camelCase. For example:
    • $this->dbforge->add_field to $this->forge->addField
    • $this->dbforge->add_key to $this->forge->addKey
    • $this->dbforge->create_table to $this->forge->createTable
    • $this->dbforge->drop_table to $this->forge->dropTable
  8. (optional) You can change the array syntax from array(...) to [...]
  9. Upgrade the migration table, if you use the same database.
    • (development) Run the CI4 migration in the development environment or similar, with a brand-new database, to create the new migration table.
    • (development) Export the migration table.
    • (production) Drop (or rename) the existing CI3 migration table.
    • (production) Import the new migration table and the data.

Code Example

CodeIgniter Version 3.x

Path: application/migrations:

<?php

defined('BASEPATH') OR exit('No direct script access allowed');

class Migration_Add_blog extends CI_Migration
{
    public function up()
    {
        $this->dbforge->add_field(array(
            'blog_id' => array(
                'type'           => 'INT',
                'constraint'     => 5,
                'unsigned'       => true,
                'auto_increment' => true,
            ),
            'blog_title' => array(
                'type'       => 'VARCHAR',
                'constraint' => '100',
            ),
            'blog_description' => array(
                'type' => 'TEXT',
                'null' => true,
            ),
        ));
        $this->dbforge->add_key('blog_id', true);
        $this->dbforge->create_table('blog');
    }

    public function down()
    {
        $this->dbforge->drop_table('blog');
    }
}

CodeIgniter Version 4.x

Path: app/Database/Migrations:

<?php

namespace App\Database\Migrations;

use CodeIgniter\Database\Migration;

class AddBlog extends Migration
{
    public function up()
    {
        $this->forge->addField([
            'blog_id' => [
                'type'           => 'INT',
                'constraint'     => 5,
                'unsigned'       => true,
                'auto_increment' => true,
            ],
            'blog_title' => [
                'type'       => 'VARCHAR',
                'constraint' => '100',
            ],
            'blog_description' => [
                'type' => 'TEXT',
                'null' => true,
            ],
        ]);
        $this->forge->addKey('blog_id', true);
        $this->forge->createTable('blog');
    }

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

Search & Replace

You can use the following table to search & replace your old CI3 files.

Search Replace
extends CI_Migration extends Migration
$this->dbforge->add_field $this->forge->addField
$this->dbforge->add_key $this->forge->addKey
$this->dbforge->create_table $this->forge->createTable
$this->dbforge->drop_table $this->forge->dropTable