Modification of Magento 2 database core table

Question

I am getting this error in UpgradeSchema. I have added one column in these core tables, functionalities are working good. According to coding standard it shows warning message.

 ----------------------------------------------------------------------
     60 | WARNING | Modification of magento database core table
        |         | 'sales_order'
     78 | WARNING | Modification of magento database core table
        |         | 'sales_order_grid'
 ----------------------------------------------------------------------

I have attached my code below

<?php
namespace frontname\modulename\Setup;

use Magento\Framework\Setup\UpgradeSchemaInterface;
use Magento\Framework\Setup\ModuleContextInterface;
use Magento\Framework\Setup\SchemaSetupInterface;
use Magento\Framework\DB\Ddl\Table;

class UpgradeSchema implements UpgradeSchemaInterface
{
    public function upgrade(SchemaSetupInterface $setup, ModuleContextInterface $context)
    {
        $installer = $setup;
        $customerGroupTable = $setup->getConnection()->describeTable($setup->getTable('customer_group'));
        $customerGroupIdType = $customerGroupTable['customer_group_id']['DATA_TYPE'] == 'int'
            ? \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER : $customerGroupTable['customer_group_id']['DATA_TYPE'];
        $installer->startSetup();
        if (version_compare($context->getVersion(), '2.0.1') < 0) {
            $eavTable = $installer->getTable('sales_order');
            $columns = [
                'is_wallet_quote' => [
                    'type' => \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
                    'nullable' => false,
                    'comment' => 'Is this quote for wallet?',
                ],
                'holded_quote_id' => [
                    'type' => \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
                    'nullable' => false,
                    'comment' => 'Holded Quote Id',
                ],

            ];
            $connection = $installer->getConnection();
            foreach ($columns as $name => $definition) {
                $connection->addColumn($eavTable, $name, $definition);
            }
            $eavTable = $installer->getTable('sales_order_grid');
            $columns = [
                'is_wallet_quote' => [
                    'type' => \Magento\Framework\DB\Ddl\Table::TYPE_INTEGER,
                    'nullable' => false,
                    'comment' => 'Is this quote for wallet?',
                ],
            ];
            $connection = $installer->getConnection();
            foreach ($columns as $name => $definition) {
                $connection->addColumn($eavTable, $name, $definition);
            }
        }
        $installer->endSetup();
    }
}

Anyone have any idea about this? Thanks in Advance

Answer 1

It is not considered a good practice to add or update anything in the structure of Magento.

A better way to do this is to add a new table of your own and add the elements needed as foreign keys if you need anything.

A good explanation is here (However, the explanation was in regards to Magento1, but I think the standard shall remain the same.)

An example to do this can be:-

addForeignKey(
                $installer->getFkName(
                    'yourTable',
                    'yourTable_id',
                    'catalog_product_entity',
                    'entity_id'
                ),
                'entity_id',
                $installer->getTable('catalog_product_entity'),
                'entity_id',
                \Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
            )