Skip to main content

What startSetup() and endSetup() methods actually does?

The startSetup() and endSetup() methods are used in setup scripts. They are often at the beginning and the end of an upgrade/install method, like in “upgrade()” method of Magento/Catalog/Setup/UpgradeData.php

The question is “do you really need them?” Or does it just “look necessary”? This blog post explores what these functions do and then explains when you do and do not need to use these methods.

Let’s see what these methods are doing.

First, startSetup():

public function startSetup() { 

 $this->rawQuery("SET SQL_MODE=''"); 

$this->rawQuery("SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0"); 

 $this->rawQuery("SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO'"); 

 return $this; 

}

1. Disable foreign keys check. It may be necessary in some rare cases (for example, in a case of cyclic references between tables), but it’s not needed in common situations. It even may lead to hiding real problems with the upgrade script, like if inserted values really break the integrity of the database.

2. Disable generation of auto-increment values when ‘0’ is inserted. It may also be useful in some cases, such as when you are certain that you’re going to insert ‘0’ values and you want them to be treated as ‘0’s, instead of defaulting to auto-incrementing. This type of scenario is not necessary for common install/upgrade scripts.

Then, endSetup() just rolls back both foreign keys check and auto-increment behavior to the previous state:

 public function endSetup() { 

    $this->rawQuery("SET SQL_MODE=IFNULL(@OLD_SQL_MODE,'')"); 

     $this->rawQuery("SET FOREIGN_KEY_CHECKS=IF(@OLD_FOREIGN_KEY_CHECKS=0, 0,     1)"); 

  return $this; 

 }

 Do you really need this for every install/upgrade? Probably not. Use startSetup() and endSetup() selectively, only for the cases where you really have some data or schema changes that are impossible without modifying default MySQL behavior.

I would recommend using these methods only when you really need such functionality during your upgrade. It would keep the foreign keys validation in place, as it may help discover potential data corruption issues.

conclusion:

==============

1:By default, don’t use startSetup() and endSetup() combination in your setup scripts. Most likely, you don’t need them.

2:The startSetup() and endSetup() may be helpful and you should use them if you want to:

   1:disable foreign key checks, or

   2:disable auto-increment for ‘0’ values. 

Labels:

Comments

Post a Comment

Popular posts from this blog

magento 1 extension converted in to magento 2 process

Simple Install =================================== Download as a zip below link. unzip and upload it to your public_html or other rootdoc directory. https://github.com/magento/code-migration. login to your server via shell switch to the code-migration-develop directory by running following command   cd code-migration-develop Run command following command in root directory of this toolkit composer instal Before running the migration, the following directories need to be prepared: ===================================== * `<src>` - Directory that contains custom Magento 1.x code that is intended to be migrated. The code must follow the Magento 1.x directory structure.   Magento1.x core files must not be included. * `<dst>` - Empty directory for the toolkit to put the generated Magento 2 code to * `<m1>` - Directory that contains: * Vanilla Magento 1.x codebase, and * Custom Magento 1.x code same as...
11 comments
Read more

Magento 2 product collection Filtering multi-select attribute values

  If you have multi-select attribute of product like below If you want filter value for this option Use below syntax to get product data: ->addAttributeToFilter('store_model', array('finset' => $params['store_model'])) finset key is used for multiselect attribute filter. $objectManager = \Magento\Framework\App\ObjectManager::getInstance(); $products = $objectManager->get('Magento\Catalog\Model\Product')         ->getCollection()         ->addAttributeToSelect('*')         ->addAttributeToSelect('store_brand')         ->addAttributeToSelect('store_model')         ->addAttributeToSelect('store_year')         ->addAttributeToFilter('store_brand', array('finset' => $params['store_brand']))         ->addAttributeToFilter('store_model', array('finset' => $params['store_model']))         ->ad...
6 comments
Read more

Magento Debug HEADERS ALREADY SENT error

When you  receiving the following error in  system.log file: app\code\core\Mage\Core\Controller\Response\Http.php:44  [1] \www.pawan.com\lib\Zend\Controller\Response\Abstract.php:727  [2]  \www.pawan.com\app\code\core\Mage\Core\Controller\Response\Http.php:75  [3]  \www.pawan.com\app\code\core\Mage\Core\Controller\Varien\Front.php:188  [4]  \www.pawan.com\app\code\core\Mage\Core\Model\App.php:304  [5]  \www.pawan.com\app\Mage.php:596  [6]  \www.pawan.com\index.php:81 if you have no idea what file is causing this. Here is the steps to debug. That error is thrown from Mage_Core_Controller_Response_Http -> sendHeaders(). This function calls the super class function that actually does the check to see whether or not headers have already been sent, Zend_Controller_Response_Abstract -> canSendHeaders(). The Zend_Controller_Response_Abstract class handles, among other things, sending response header...
6 comments
Read more