Magento mysql table install, create and upgrade scripts using custom module

Here is the code to create or update magento mysql table. This module helps to create new table.
"app/etc/modules/Company_Track.xml"

  
      
          true
          local
      
  

"app/code/local/Company/Track/etc/config.xml"

   
    
        0.1.0
   


    
       
            
                Company_Track
                Company_Track_Model_Mysql4_Setup
                
  
                    core_setup
                
        
    

"app/code/local/Company/Track/Model/Mysql/Setup.php"

class Company_Track_Model_Mysql4_Setup extends Mage_Catalog_Model_Resource_Eav_Mysql4_Setup
{
}

Here is the code to create table query.
"app/code/local/Company/Track/sql/track_setup/mysql4-install-0.1.0.php"

$installer = $this;
 
$installer->startSetup();
 
$installer->run("
 
-- DROP TABLE IF EXISTS {$this->getTable('customer_track')};
CREATE TABLE IF NOT EXISTS {$this->getTable('customer_track')} (
`id` INT UNSIGNED NOT NULL ,
`sku` varchar(64) NOT NULL ,
`customer_id` INT NOT NULL ,
`region` varchar(255) NOT NULL ,
`country_id` char(2) NOT NULL
) ;

"); 
$installer->endSetup();

If you want to update mysql table using update query you have to use the below coding. Here im going to remove last name required option to not required.
"app/code/local/Company/Track/sql/track_setup/mysql4-upgrade-0.1.0-0.1.1.php"

/* @var $eav Mage_Eav_Model_entity_Setup */
$eav = Mage::getModel('eav/entity_setup', 'core_setup');
$eav->updateAttribute('customer_address', 'lastname', 'is_required', false);