Infinite pole Classification of PHP

First set up the classification information table:

1 CREATE TABLE IF  not EXISTS' Category ' (2' CategoryId 'smallint(5) unsigned not NULLAuto_increment,3' ParentID 'smallint(5) unsigned not NULL DEFAULT '0',4' CategoryName 'varchar( -) not NULL,5   PRIMARY KEY(' categoryId ')6)  ;

Insert several data:

1 INSERT  into' Category ' (' categoryId ', ' parentid ', ' CategoryName ')VALUES2(1,0,'PHP'),3(2,0,'Java'),4(3,0,'C + +'),5(4,1,'PHP Basics'),6(5,1,'PHP Open Source data'),7(6,1,'PHP Framework'),8(7,2,'Java Se'),9(8,2,'Java EE'),Ten(9,2,'Java Me'), One(Ten,3,'BASIC Programming for C + +'), A( One,3,'d/C + + system development'), -( A,3,'C Embedded Programming'), -( -,3,'C + + application development'), the( -, -,'C + + desktop application development'), -( the, -,'C + + game development');

Here is the PHP code:

1<?PHP2 //PHP Infinite Class classification3 4 //Get direct subcategories of a category5 functionGetsons ($categorys,$catId=0){6     $sons=Array();7     foreach($categorys  as $item){8         if($item[' ParentID ']==$catId)9             $sons[]=$item;Ten     } One     return $sons; A } -  - //get all subcategories of a category the functionGetsubs ($categorys,$catId=0,$level=1){ -     $subs=Array(); -     foreach($categorys  as $item){ -         if($item[' ParentID ']==$catId){ +             $item[' Level ']=$level; -             $subs[]=$item; +             $subs=Array_merge($subs, Getsubs ($categorys,$item[' CategoryId '],$level+1)); A              at         } -              -     } -     return $subs; - } -  in //get all the parent categories for a category - //Method one, recursive to functionGetparents ($categorys,$catId){ +     $tree=Array(); -     foreach($categorys  as $item){ the         if($item[' CategoryId ']==$catId){ *             if($item[' ParentID ']>0) $                 $tree=Array_merge($tree, Getparents ($categorys,$item[' ParentID ']));Panax Notoginseng             $tree[]=$item;  -              Break;  the         } +     } A     return $tree; the } +  - //method Two, iteration $ functionGetParents2 ($categorys,$catId){ $     $tree=Array(); -      while($catId! = 0){ -         foreach($categorys  as $item){ the             if($item[' CategoryId ']==$catId){ -                 $tree[]=$item;Wuyi                 $catId=$item[' ParentID ']; the                  Break;  -             } Wu         } -     } About     return $tree; $ } -  -  - //Test Section A $pdo=NewPDO (' Mysql:host=localhost;dbname=test ', ' root ', ' 8888 '); + $stmt=$pdo->query ("SELECT * from category ORDER by CategoryId"); the $categorys=$stmt->fetchall (PDO::FETCH_ASSOC); -  $ $result=getsons ($categorys, 1); the foreach($result  as $item) the     Echo $item[' CategoryName ']. ' <br> '; the Echo' ; the  - $result=getsubs ($categorys, 0); in foreach($result  as $item) the     Echo str_repeat(‘ ‘,$item[' Level ']).$item[' CategoryName ']. ' <br> '; the Echo' ; About  the $result=getparents ($categorys, 7); the foreach($result  as $item) the     Echo $item[' CategoryName ']. ' >> '; + Echo' ; -  the $result=getparents2 ($categorys, 15);Bayi foreach($result  as $item) the     Echo $item[' CategoryName ']. ' >> '; the?>

Here is the result of the run:

Infinite pole Classification of PHP