Magento 2 add new column to existing table on a running webshop

Question

I know there are a few posts regarding how to add a new column to the existing table in Magento 2. My concern is if I already have a webshop that is running, can I still add a new column to a table?

for example, I want to add a new column to the table sales_order_item in a webshop database that already has a lot of data existing.

Answer 1

You need to use below cod in your setup script of your custom module

<?php

namespace Vendor\Modulename\Setup;


use Magento\Sales\Setup\SalesSetupFactory;
use Magento\Eav\Model\Entity\Attribute\SetFactory as AttributeSetFactory;
use Magento\Framework\Setup\InstallDataInterface;
use Magento\Framework\Setup\ModuleContextInterface;
use Magento\Framework\Setup\ModuleDataSetupInterface;

/**
 * InstallData
 *
 * @codeCoverageIgnore
 */
class InstallData implements InstallDataInterface
{


    /**
     * SalesSetupFactory
     *
     * @var SalesSetupFactory
     */
    protected $salesSetupFactory;



    /**
     * Constructor
     * @param SalesSetupFactory $salesSetupFactory
     */
    public function __construct(
        SalesSetupFactory $salesSetupFactory
    ) {
        $this->salesSetupFactory = $salesSetupFactory;
    }


    /**
     * Install
     *
     * @param ModuleDataSetupInterface $setup
     * @param ModuleContextInterface $context
     */
    public function install(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
    {

        /** @var \Magento\Sales\Setup\SalesSetup $salesInstaller */
        $salesInstaller = $this->salesSetupFactory->create(['resourceName' => 'sales_setup', 'setup' => $setup]);

        $salesInstaller->addAttribute('order_item', 'test', ['type' => \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER, 'length'=> 10, 'visible' => false,'nullable' => true,]);
    }

}