getTable('comments'); $modified = false; if (!$table->hasColumn('reference_id')) { $modified = true; $table->addColumn('reference_id', Types::STRING, [ 'notnull' => false, 'length' => 64, ]); } if (!$table->hasColumn('meta_data')) { $modified = true; $table->addColumn('meta_data', Types::TEXT, [ 'notnull' => false, 'default' => '', ]); } return $modified ? $schema : null; } }