Вот код поискового мамбота, теперь может будет проще подсказать.
<?php
defined( '_VALID_MOS' ) or die( 'Прямой доступ запрещен.' );
$_MAMBOTS->registerFunction( 'onSearch', 'botSearchVM' );
function botSearchVM( $text, $phrase='', $ordering='' ) {
  global $database;
  $text = trim( $text );
  if ($text == '') {
    return array();
  }
   $wheres = array();
   switch ($phrase) {
      case 'exact':
         $wheres2 = array();
         $wheres2[] = "LOWER(product_name) LIKE '%$text%'";
         $wheres2[] = "LOWER(product_sku) LIKE '%$text%'";
         $wheres2[] = "LOWER(product_desc) LIKE '%$text%'";
         $wheres2[] = "LOWER(product_s_desc) LIKE '%$text%'";
         $wheres2[] = "LOWER(product_url) LIKE '%$text%'";
         $where = '(' . implode( ') OR (', $wheres2 ) . ')';
         break;
      case 'all':
      case 'any':
      default:
         $words = explode( ' ', $text );
         $wheres = array();
         foreach ($words as $word) {
            $wheres2 = array();
            $wheres2[] = "LOWER(product_name) LIKE '%$text%'";
            $wheres2[] = "LOWER(product_sku) LIKE '%$text%'";
            $wheres2[] = "LOWER(product_desc) LIKE '%$text%'";
            $wheres2[] = "LOWER(product_s_desc) LIKE '%$text%'";
            $wheres2[] = "LOWER(product_url) LIKE '%$text%'";
            $wheres[] = implode( ' OR ', $wheres2 );
         }
         $where = '(' . implode( ($phrase == 'all' ? ') AND (' : ') OR ('), $wheres ) . ')';
         break;
   }
   switch ($ordering) {
      case 'newest':
      default:
         $order = '#__vm_product.cdate DESC';
         break;
      case 'oldest':
         $order = '#__vm_product.cdate ASC';
         break;
      case 'popular':
         $order = '#__vm_product.product_name ASC';
         break;
      case 'alpha':
         $order = '#__vm_product.product_name ASC';
         break;
      case 'category':
         $order = '#__vm_category.category_name ASC';
         break;
   }
    
  
  $database->setQuery( " SELECT id, name FROM  `#__menu` WHERE link LIKE '%com_virtuemart%' AND published=1 AND access=0");
  $database->loadObject( $Item );
  $ItemName = !empty( $Item->name ) ? $Item->name : "Shop";
  $Itemid = !empty( $Item->id ) ? $Item->id : "1";
  $query = "SELECT product_name as title,"
               . "\n    FROM_UNIXTIME( #__vm_product.cdate, '%Y-%m-%d %H:%i:%s'  ) AS created," 
               . "\n    product_s_desc AS text,"
               . "\n    CONCAT('$ItemName/',#__vm_category.category_name) as section,"
               
               . "\n    CONCAT('index.php?option=com_virtuemart&page=shop.product_details&flypage=',#__vm_category.category_flypage,'&category_id=',#__vm_category.category_id,'&product_id=', #__vm_product.product_id, '&Itemid=".$Itemid."' ) as href,"
               . "\n    '2' as browsernav"
               . "\n FROM #__vm_product"
               . "\n LEFT JOIN `#__vm_product_category_xref` ON `#__vm_product_category_xref`.`product_id` = `#__vm_product`.`product_id`"
               . "\n LEFT JOIN `#__vm_category` ON `#__vm_product_category_xref`.`category_id` = `#__vm_category`.`category_id`"
               . "\n WHERE $where"
            . "\n AND (product_parent_id='' OR product_parent_id='0')"
            . "\n AND product_publish='y'"
               . "\n ORDER BY $order" ;
               
  $database->setQuery( $query );
  $row = $database->loadObjectList();
  
  return $row;
}
?>