```
$i=0;
function deeploop( $i ){
  global $i;
  $i++;
  echo $i;
  if( $i<10 ){
    deeploop($i);
  }

}

function deeploop( ){
  static $i=0;
  $i++;
  echo $i;
  if( $i<10 ){
    deeploop($i);
  }

}


function deeploop( &$i=0 ){
  $i++;
  echo $i;
  if( $i<10 ){
    deeploop($i);
  }

}

```

  ```
    #父级Id递归法
    CREATE TABLE `deepcate`(
      `id` int(11) NOT NULL AUTO_INCREMENT PRIMARY KEY,
      `pid` int(11) NOT NULL DEFAULT 0,
      `catename` char(25) NOT NULL,
      `cateorder` int(6) ,
      `createtime` date
    )ENGINE=INNODB default CHARSET=utf8;
    
    
    //数据
    INSERT INTO `deepcate` VALUES(1,0,'图片',null,'2016-11-01'),
                  ( 2,1,'美女',null,'2016-11-01'),
                  ( 3,1,'新闻',null,'2016-11-01'),
                  ( 4,2,'足球宝贝',null,'2016-11-01'),
                  ( 5,2,'日韩明星',null,'2016-11-01'),
                  ( 6,5,'美女写真',null,'2016-11-01');
                  
    #全路径
    CREATE TABLE `qljcate` (
      `id` int(11) NOT NULL,
      `path` char(255) ,
      `catename` char(25) NOT NULL,
      `cateorder` int(6),
      `createtime` date
    )ENGINE=INNODB default CHARSET=utf8;
    
    INSERT INTO `qljcate` VALUES( 1,null,'图片',null,'2016-11-01'),
                  ( 2,1,'美女图片',null,'2016-11-01'),
              ( 3,1,2,'足球宝贝',null,'2016-11-01'),
                  ( 4,1,2,'日韩明星',null,'2016-11-01'),
                  ( 5,1,2,4,'美女写真',null,'2016-11-01');
  ```

  ```
    #父级Id递归法
    CREATE TABLE `deepcate`(
      `id` int(11) NOT NULL AUTO_INCREMENT PRIMARY KEY,
      `pid` int(11) NOT NULL DEFAULT 0,
      `catename` char(25) NOT NULL,
      `cateorder` int(6) ,
      `createtime` date
    )ENGINE=INNODB default CHARSET=utf8;
    
    
    //数据
    INSERT INTO `deepcate` VALUES(1,0,'图片',null,'2016-11-01'),
                  ( 2,1,'美女',null,'2016-11-01'),
                  ( 3,1,'新闻',null,'2016-11-01'),
                  ( 4,2,'足球宝贝',null,'2016-11-01'),
                  ( 5,2,'日韩明星',null,'2016-11-01'),
                  ( 6,5,'美女写真',null,'2016-11-01');
                  
    #全路径
    CREATE TABLE `qljcate` (
      `id` int(11) NOT NULL,
      `path` char(255) ,
      `catename` char(25) NOT NULL,
      `cateorder` int(6),
      `createtime` date
    )ENGINE=INNODB default CHARSET=utf8;
    
    INSERT INTO `qljcate` VALUES( 1,null,'图片',null,'2016-11-01'),
                  ( 2,1,'美女图片',null,'2016-11-01'),
              ( 3,1,2,'足球宝贝',null,'2016-11-01'),
                  ( 4,1,2,'日韩明星',null,'2016-11-01'),
                  ( 5,1,2,4,'美女写真',null,'2016-11-01');
  ```

```
  #pid 父级id实现法
  function GetAllcate( $id,&$result=array() ){
    $sql = "SELECT * FROM deepcate WHERE pid in ({$id})";
    $query = mysql_query( $sql );
    $row = mysql_fetch_assoc( $query );
    if( mysql_num_rows($row)>0 )
    {
      $idlist = array();
      while( $row ){
        $result[] = $row;
        $idlist[] = $row['id']; 
      }
      $id = implode(',',$idlist);
      GetAllcate( $id,$result );
    
    }
    
    $result = array_unique( $result );
    return $result;
  }
  ```