*/ $installer = $this; /* @var $installer Mage_Core_Model_Resource_Setup */ $installer->startSetup(); $table = $installer->getTable('tax_rate'); $installer->getConnection()->dropColumn($table, 'tax_county_id'); $installer->run("update {$table} set tax_postcode='*' where tax_postcode='' or tax_postcode is null"); $installer->endSetup();