Ever wondered what they do? Basically they disable and then enable foreign key checks, and set the SQL mode to NO_AUTO_VALUE_ON_ZERO, then back to the old SQL mode. Below is the code taken from Varien_Db_Adapter_Pdo_Mysql:
/**
* Run additional environment before setup
*
* @return Varien_Db_Adapter_Pdo_Mysql
*/
public function startSetup()
{
$this->raw_query("SET SQL_MODE=''");
$this->raw_query("SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0");
$this->raw_query("SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO'");
return $this;
}
/**
* Run additional environment after setup
*
* @return Varien_Db_Adapter_Pdo_Mysql
*/
public function endSetup()
{
$this->raw_query("SET SQL_MODE=IFNULL(@OLD_SQL_MODE,'')");
$this->raw_query("SET FOREIGN_KEY_CHECKS=IF(@OLD_FOREIGN_KEY_CHECKS=0, 0, 1)");
return $this;
}
Posted by Mike Whitby to Magento (2012-07-05 14:25)