减少php网上商店的数据库调用

Question

I'm looking for a way to prevent repeated calls to the database if the item in question has already been loaded previously. The reason is that we have a lot of different areas that show popular items, latest releases, top rated etc. and sometimes it happens that one item appears in multiple lists on the same page.

I wonder if it's possible to save the object instance in a static array associated with the class and then check if the data is actually in there yet, but then how do I point the new instance to the existing one?

Here's a draft of my idea:

 $baseball = new Item($idOfTheBaseballItem);  
 $baseballAgain = new Item($idOfTheBaseballItem);

 class Item 
 {  
      static $arrItems = array();  

      function __construct($id) {
           if(in_array($id, self::arrItems)){
               // Point this instance to the object in self::arrItems[$id]
               // But how?
          }
          else {
              // Call the database  

              self::arrItems[id] = $this;
          }
      }
 }

If you have any other ideas or you just think I'm totally nuts, let me know.

Answer 1

You should know that static variables only exist in the page they were created, meaning 2 users that load the same page and get served the same script still exist as 2 different memory spaces.

You should consider caching results, take a look at code igniter database caching

What you are trying to achieve is similar to a singleton factory

$baseball = getItem($idOfTheBaseballItem);  
$baseballAgain =getItem($idOfTheBaseballItem);

function getItem($id){
    static $items=array();
    if(!isset($items[$id])$items[$id]=new Item($id);
    return $items[$id];
}

class Item{  
    // this stays the same
}

P.S. Also take a look at memcache. A very simple way to remove database load is to create a /cache/ directory and save database results there for a few minutes or until you deem the data old (this can be done in a number of ways, but most approaches are time based)