console/migrations/m160321_132138_project_add_status.php

<?php

use yii\db\Migration;

class m160321_132138_project_add_status extends Migration
{
    public function up()
    {
        $this->addColumn('{{%project}}', 'hidden', $this->integer()->defaultValue(0));
    }

    public function down()
    {
        $this->dropColumn('{{%project}}', 'hidden');
    }
}