SchemaUpgrade issue in Magento 2

Question

Today I'm learning Upgrading schema and Upgrading data, for this I am created simple table with version0.0.1 and it's working fine. Later I written code for UpgradeSchema. But it is not working for me. For this stuff I have written below code.

UpgradeSchema.php

<?php

namespace Training\HelloWorld\Setup;

use Magento\Framework\Setup\SchemaSetupInterface;
use Magento\Framework\Setup\ModuleContextInterface;

class UpgradeSchema implements \Magento\Framework\Setup\UpgradeSchemaInterface
{

    public function upgrade(SchemaSetupInterface $setup, ModuleContextInterface $context){

        $installer = $setup;

        $installer->startSetup();
        if (version_compare($context->getVersion(), "0.0.1", "<")) {
            //Your upgrade script
        }
        if (version_compare($context->getVersion(), '0.0.1', '>')) {
            $installer->getConnection()->addColumn(
                $installer->getTable('helloworld'),
                'long_description',
                [
                    'type' => \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
                    'length' => 255,
                    'nullable' => false,
                    'comment' => 'Long Description'
                ]
            );
        }
        $installer->endSetup();

    }

}

after this I run the php bin/magento setup:upgrade CLI Command. it's working fine and setup_module table also converted versions as below.

1. Previously Training_HelloWorld 0.0.1 0.0.1
2. After upgrade command Training_HelloWorld 0.1.1 0.1.1 converted successfully.

but My table is not added new column.

Could you please suggest me where I went wrong?

Answer 1

Replace below code to your version condition

if (version_compare($context->getVersion(), '0.0.1') < 0) {
        $installer->getConnection()->addColumn(
            $installer->getTable('helloworld'),
            'long_description',
            [
                'type' => \Magento\Framework\DB\Ddl\Table::TYPE_TEXT,
                'length' => 255,
                'nullable' => false,
                'comment' => 'Long Description'
            ]
        );
    }

You need to add previous version value (0.0.1) to setup_module table.

Run setup:upgrade command and check.