//获得指定的规格的价格
//param mix spec 规格ID的数组或者逗号分隔的字符串
function spec_price($spec){
  if(!empty($spec)){
    if(is_array($spec)){
      foreach($spec as $key=>$val){
        $spec[$key]=addslashes($val);
      }
    }else{
      $spec=addslashes($spec);
    }
    $where=db_create_in($spec,'goods_attr_id');
    $sql='select sum(attr_price) as attr_price from '.$GLOBALS['ecs']->table('goods_attr')." where $where";
    $price=floatval($GLOBALS['db']->getOne($sql));
  }else{
    $price=0;
  }
  return $price;
}