How to implement unlimited classification in PHP

Infinite classification is a design technique that is often used in development. This article mainly introduces the implementation method of infinite classification in PHP. If you need it, you can learn about it.

Infinite classification is a design technique that is often used in development, such as website directories, department structures, and article classifications. The author feels that it plays a great role in designing the hierarchical structure of tables. For example, on some platforms,

Fill in the inviter, it is a superior-subordinate relationship. The superior will have multiple subordinates, and the subordinates will have their own branches. Most of them are implemented using recursive ideas. Without further ado, let’s first review the implementation of recursion

Recursion (a programming technique in which a program calls itself):

1. $_GLOBALS[result]

2. static $result

3. Parameter reference &

Example: Traverse 1-10

$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);
  }
 
}

1. Unlimited classification implementation:

1. Set the parent id in the table design and set the top parent id to 0 to establish a family tree; each category needs to record its parent id. (pid=0 represents the top level)

id pid catename cateorder createtime (primary key id, parent id, category name, category sorting, creation time)

Examples: Category directory structure of website; Category structure of catering; Structure of comments

2. Unlimited classification of the full path (record all parent IDs in order in one field)

id path catename cateorder createtime (primary key id, parent id in comma-separated order, category name, category sorting, creation time)

Advantages and disadvantages:

Full path query is convenient; additionally, data maintenance is slightly more complicated when moving classification;

2. Example implementation (website directory):

Classification table:

 #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');

Get the directory path where the image is located:

#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');

*be careful:

A mobile category cannot be moved below itself and its subcategories; a category can be deleted (only the lowest category can be deleted, and categories without subcategories; in other words, it can only be deleted from the lowest level).

Thinking about all the image categories under image types?​

 #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;
  }

This method is more suitable for querying all books and articles under the parent category. . . Of course, the full path can be obtained directly, so I won’t mention it here.

In actual operation, we can design a reasonable table structure according to the actual situation.

For example, if a chain store implements product management, there will be a superior-subordinate relationship in the store's account settings. Depending on the partition of the agent point, there may be such subordinates who have their own subordinates. Then using this unlimited classification method will be more flexible to face this. With this kind of relationship system, you only need to set each account level to set permission distribution for different stores.