CakePHP 3.x Migrations example

<?php
use Migrations\AbstractMigration;
use Cake\Log\Log;

/**
 * Class AdministratorsTableMigration
 */
class AdministratorsTableMigration extends AbstractMigration
{

    /**
     * @var string
     */
    private $_tableName;

    /**
     * @var string
     */
    private $_tablePrefix;

    public function init()
    {
        $this->_tableName = '"Administrators"';
        $this->_tablePrefix = 'administrators';
    }

    public function up()
    {
        Log::info("Trying to create {$this->_tableName} table");

        $administratorsTable = $this->table($this->_tablePrefix);

        if ($administratorsTable->exists()) {
            return Log::warning("Table {$this->_tableName} already exists");
        }

        $administratorsTable
            ->addPrimaryKey('id')
            ->addColumn('username', 'char', [
                'length' => 25,
                'null' => false
            ])
            ->addColumn('password', 'char', [
                'length' => 255,
                'null' => false
            ])
            ->addColumn('email', 'char', [
                'length' => 50,
                'null' => false
            ])
            ->addColumn('first_name', 'char', [
                'length' => 50,
                'null' => false
            ])
            ->addColumn('last_name', 'char', [
                'length' => 50,
                'null' => false
            ])
            ->addColumn('avatar', 'char', [
                'length' => 255,
                'default' => '/img/no-avatar.png'
            ])
            ->addColumn('active', 'boolean', [
                'default' => 0
            ])
            ->addTimestamps()
            ->create();

        return Log::notice("Table {$this->_tableName} has been created");
    }

    public function down()
    {
        if ($this->table($this->_tablePrefix)->exists()) {
            $this->table($this->_tablePrefix)->drop();
            return Log::info("Table {$this->_tableName} has been dropped");
        }

        return Log::warning("Table {$this->_tableName} does not exists");
    }

}