Programatically add cross sell products to all products within a certain category

Question

I'm not sure if this is even possible but say for example i have a category called X with 100 products in it, can i add say 3 products to all them 100 products in that particular category without manually going through every single product selecting which product(s) i would like to cross sell.

Answer 1

You can try below code:

$categoryId= 123;
$categoryProducts = Mage::getModel('catalog/category')->load($categoryId)->getProductCollection();
foreach($categoryProducts as $product){
     $param = array();
     $crosssells = $product->getCrossSellProducts();
     foreach ($crosssells as $item) {
           $param[$item->getId()] = array('position' =>$item->getPosition());
     }
    $newCrossSellProductsIds=array(4,5,6);
    foreach ($newCrossSellProductsIds as $productID) {
     if (!isset($param[$productID])){ 
          $param[$productID]= array(
                                    'position'=>1
                                   );
      }
     }
   $product->setCrossSellLinkData($param);
   $product->save();
}