changing collation script

collation.php

<?php
require_once 'abstract.php';

class Atwix_Collation_Shell extends Mage_Shell_Abstract
{
    /**
     * Validate arguments
     *
     */
    protected function _validate()
    {
        return true;
    }

    public function run()
    {
        $write = Mage::getSingleton('core/resource')->getConnection('core_write');
        $showCollationQuery = 'show variables like "%collation_database%"';
        $res = $write->fetchRow($showCollationQuery);
        $dbConfig = $write->getConfig();
        if ($res['Value'] != 'utf8_general_ci') {
            $generalQuery = 'ALTER DATABASE ' . $dbConfig['dbname'] . ' CHARACTER SET utf8 COLLATE utf8_general_ci;';
            $write->query($generalQuery);
        }

        $query = 'SELECT T.table_name, T.table_collation, CCSA.character_set_name FROM information_schema.`TABLES` T,
information_schema.`COLLATION_CHARACTER_SET_APPLICABILITY` CCSA
WHERE CCSA.collation_name = T.table_collation
AND T.table_schema = "' . $dbConfig['dbname'] . '"
AND T.table_collation != "utf8_general_ci"
AND T.table_name not like "%tmp%"
AND T.table_name not like "%_bak%";';
        $tablesInfo = $write->fetchAll($query);
        echo "Total tables to process: " . count($tablesInfo) . PHP_EOL;;
        foreach ($tablesInfo as $tableInfo) {
            $query = 'ALTER TABLE ' . $tableInfo['table_name'] . ' CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci;';
            echo 'processing table ' . $tableInfo['table_name'] . PHP_EOL;
            Mage::log('processing table ' . $tableInfo['table_name'], null, 'atwix_collation.log');
            $write->query($query);
        }
    }
}

$shell = new Atwix_Collation_Shell();
$shell->run();

?>