Magento: Want to use negative position values in Category Product Relation? Just include this MySQL update routine and rerun the indexer for catalog_category_product. Problem: Table catalog_category_product with its column position is type signed while the column position in the indexers anchor idx and tmp table are unsigned. Unsigned columns ca…

mysql4-upgrade-0.0.x-0.0.y.php

<?php
/**
 * @var $installer Mage_Catalog_Model_Resource_Eav_Mysql4_Setup
 */
$installer = $this;
$installer->startSetup();
$tables = array(
    $installer->getTable('catalog/category_anchor_products_indexer_idx'),
    $installer->getTable('catalog/category_anchor_products_indexer_tmp')
);
foreach ($tables as $table) {
    $installer->getConnection()->modifyColumn(
        $table,
        'position',
        array(
            'type'     => Varien_Db_Ddl_Table::TYPE_INTEGER,
            'unsigned' => FALSE,
            'nullable' => TRUE,
            'default'  => null,
            'comment'  => 'Position'
        )
    );
}
$installer->endSetup();