I’m making an attempt so as to add an attribute like product_id for merchandise that can have auto_increment.

What I did up to now and isn’t working:

and so forth/config.xml

<?xml model="1.0"?>
<config>
  <modules>
    <Mymodule>
      <model>0.1.0</model>
    </Mymodule>
  </modules>
  <world>
    <helpers>
      <mymodule>
        <class>Mymodule_Helper</class>
      </mymodule>
    </helpers>
  <fashions>
                    <Mymodule>
                       <class>Mymodule_Model</class>
                    </Mymodule>
                </fashions>
    <sources>
      <mymodule_setup>
        <setup>
          <module>mymodule</module>
        </setup>
        <connection>
          <use>core_setup</use>
        </connection>
      </mymodule_setup>
      <mymodule_write>
        <connection>
          <use>core_write</use>
        </connection>
      </mymodule_write>
      <mymodule_read>
        <connection>
          <use>core_read</use>
        </connection>
      </mymodule_read>
    </sources>
  </world>
</config>

The mannequin:

<?php
class Mymodule_Model_Myitem extends Mage_Core_Model_Abstract {
 //this methodology merely provides one to the increment id an returns the brand new one
    public operate getIncrementId(){
        return Mage::getSingleton('eav/config')
            ->getEntityType('myitem')
            ->fetchNewIncrementId();
    }

protected operate _beforeSave()
{ 

    mother or father::_beforeSave();

    if (!$this->getIncrementId()) {
        $incrementId = Mage::getSingleton('eav/config')
            ->getEntityType('custom_sku2')
            ->fetchNewIncrementId($this->getStoreId());
        $this->setIncrementId($incrementId);
    }

}

}    

and the installer script:

<?php
$set up = $this;
$install->startSetup();

$install->addEntityType('mymodule', array(
    'entity_model'          => 'mymodule',
    'increment_model'       => 'eav/entity_increment_numeric',
    'increment_per_store'   => false,
));

$entityType = Mage::getModel('eav/entity_type')->loadByCode('custom_sku2');
$entityStoreConfig = Mage::getModel('eav/entity_store')->loadByEntityStore($entityType ->getId(), 12);
$entityStoreConfig->setEntityTypeId($entityType ->getId())
    ->setStoreId(0)
    ->setIncrementPrefix("MYPREFIX")
    ->setIncrementLastId(100)
    ->save();

$install->endSetup();

Then I create an attribute the traditional means in Magento with the identify “custom_sku2” and I add this attribute in merchandise grid.
Even after save i can’t see this attribute auto increment, it’s clean.