What is the correct way to modify core column value in Magento 2?

Question

I have a requirement to remove firstname, lastname as required field from registration page which I can achieve by modifying eav_attribute table directly

UPDATE 'eav_attribute' SET 'is_required' = 0 WHERE 'entity_type_id' = 1 && 'attribute_code' = 'lastname';

(Similarly I'll update firstname and remove firstname, lastname input field from the phtml file.)

I know modifying the core tables directly is not a good practice. What are alternatives through which I can achieve the above stated requirement?

After reading Modify core tables vs custom tables and joins, I see it's recommended to create a custom table and use joins. Can someone share any example how that is done ?

Answer 1

You should create Install/Upgrade data class and use EavSetup. Here you have an exemple snippet:

class UpgradeData implements UpgradeDataInterface
{

    private $eavSetupFactory;

    public function __construct(EavSetupFactory $eavSetupFactory)
    {
    $this->eavSetupFactory = $eavSetupFactory;
    }

    public function upgrade(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
    {
    $eavSetup = $this->eavSetupFactory->create(['setup' => $setup]);

    if ($context->getVersion()
        && version_compare($context->getVersion(), '1.0.1') < 0
    ) {
        $this->updateFirstnameAttribute($eavSetup);
    }
    }

    /**
     * @param $eavSetup
     *
     * @return void
     */
    protected function updateFirstnameAttribute(EavSetup $eavSetup)
    {
    $eavSetup->updateAttribute(\Magento\Customer\Model\Customer::ENTITY, 'firstname', 'is_required', false);
    }
}

Of course you can create data provider for new attributes and do it your own way, this is just an example of possible solution for a single attribute.