Php+xml Cache How to quickly read a specified value

Php+xml Cache How to quickly read a specified value
Using XML caching
Structure is

-
-
1
B007

-
2
B001

-
3
B000

-
4
B004

-
5
B003

..............



Copy Code
More data

Now I want to quickly find
PD value of id=4
or id=4 all values for the following item
What should I write?

One more question, can XML support dynamic read values?
Like a.xml?id=4.
This type of
May I? Thank you

It's PHP.

------Solution--------------------
Reference: http://topic.csdn.net/u/20120521/03/527bc4d2-b4e0-4d6e-9ae4-021a675cfff5.html
------Solution--------------------

PHP Code

$xml =simplexml_load_file (' Bb.xml '); foreach ($xml->item as $v) {if ($v->id==4) echo "ID: $v->id
PD: $v->pd ";}
------Solution--------------------
XPath, do you have any other answers?


  

   

     PHP code 
    
[user:root time:10:28:18 path:/home/liangdong/php]$   
  PHP xpath.php PD b004[user:root time:10:28:19 path:/home/liangdong/php]$ cat xpath.php!--? php$str = <<
      
    
       
       
         1 
        
       
         B007 
        
       
       
       
         2 
        
       
          
   B001 
        
       
       
       
         3 
        
       
         B000 
        
       
       
       
         4 
        
       
         B004 
        
       
       
       
         5 
        
       
         B003 
        
 
       
       EOF, $xml = simplexml_load_string ($str, "SimpleXMLElement", libxml_noblanks), $res = $xml->xpath ("/channe L/item/id[text () =4]/parent::item/pd "), foreach ($res as $node) {echo $node->getname (). " " . $node->{0}. Php_eol;}? 
      
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