Update Magento product meta description for different store - magento

Question

i am trying to update meta description for different store but magento keep showing error :
Product with URL key already exist.
what i am trying to do i have two stores on one magento. so we want seprate meta information for different stores. so when i try to update meta info for specific store then shows me error. any one facing same problem :
$pid = Mage::getModel('catalog/product')->getResource()->getIdBySku($sku);
$product = Mage::getModel('catalog/product')->load($pid);
if($product)
{
$product->setStoreId(6);
$product->setmeta_keyword($newKeyWord);
$product->setmeta_description($newmeta_metadescription);
try {
$product->save();
echo 'Product Updated successfully --- '.$sku."\n";
}
catch (Exception $ex) {
echo $ex->getMessage();
}

Answer 1

There are lot of issue in your code:
Setter function is wrong:
$product->setMetaKeyword($newKeyWord);
$product->setMetaDescription($newmeta_metadescription);
Best way to do this:
$product = Mage::getModel('catalog/product')->load($pid);
Please use below format,which more faster then your code
$product->addAttributeUpdate($Attributecode, $value, $storeId)
then
$product->addAttributeUpdate('meta_keyword', $newKeyWord, $storeId=6);
$product->addAttributeUpdate('meta_description', $newmeta_metadescription, $storeId=6);
No need use save() function in this case.