change_mp_default_lagnuage

<?php
function change_default_language()
{
	$db    = JFactory::getDbo();
	$query = $db->getQuery(true);
	$query->select('*')
		->from('#__osmembership_plans');
	$db->setQuery($query);
	$rowFields                = $db->loadObjectList();
	$newDefaultLanguagePrefix = 'zh';
	$oldDefaultLanguage       = 'en';

	$fields = array('title', 'description', 'values', 'default_values', 'fee_values', 'depend_on_options');

	foreach ($rowFields as $rowField)
	{
		$query->clear();
		$query->update('#__osmembership_fields');
		foreach ($fields as $field)
		{
			$query->set($db->quoteName($field) . '=' . $db->quote($rowField->{$field . '_' . $newDefaultLanguagePrefix}))
				->set($db->quoteName($field . '_' . $oldDefaultLanguage) . '=' . $db->quote($rowField->{$field}));
		}
		$query->where('id = ' . $rowField->id);
		$db->setQuery($query);
		$db->execute();
	}
}