Unlimited Classification-Summary_PHP Tutorial

PHP code part:

//Unlimited classification-use path

//Principle: Split through the path to get all the pids and ids you want. The path is a field when designing the table, including a series of ids from the ancestor id to the parent id

//This method, regardless of viewing or deletion or other operations, only needs to execute the SQL statement once to achieve the desired effect

//This method is also what I prefer to use, because my principle is that if I can do without recursion, I will definitely not use recursion

$link=mysql_connect('localhost','username,'password');

if(mysql_errno()){

echo 'Database connection failed:'.mysql_error();

}

mysql_select_db('db_kind');

mysql_set_charset('utf8');

//concat(), concatenate strings into a new string

//The following code completes an infinite classification of reality

$sql="select concat(path,'-',id) as conpath,id,name,path from wx_kind order by conpath";

$result=mysql_query($sql);

while($row=mysql_fetch_assoc($result)){

$arr=array();

//Here you can choose to split the string on the path field or the newly formed conpath field

                                //One thing to note about the explode() function, no matter whether the string to be split contains characters using parameters, it will return an array containing at least one element

$count=count(explode('-',$row['path']))-1;

//str_repeat(), repeats the string, mainly to make the format clearer

$str=str_repeat(' ',$count);

echo $str.$id.'=>'.$row['name'].'

---

';

}

/***********************************

If you need to delete it now, use the same path

For example, now we want to delete the Thunder category

First find the path based on its id

**************************************/

/* $sql1="select id,path from wx_kind where id=20";

$result1=mysql_query($sql1);

$row=mysql_fetch_assoc($result1);

$id=$row['id'];

$path=$row['path'];

//Construct all paths with this category as the parent or ancestor category

$new_path=$path.'-'.$id;

//The deletion action can be performed below

$sql2="delete from wx_kind where id={$id} or path like '{$new_path}%'";

$result2=mysql_query($sql2);

if($result2 && mysql_affected_rows()){

echo 'Delete successfully! ';

}else{

echo 'Deletion failed! ';

} */

/*****************************************************/

//The method of using recursive functions, I won’t explain so much, just look at the code, the main thing is that the search method is different

function display_classify($pid=0,$num=0){

$sql="select id,name from wx_kind where pid={$pid}";

$result=mysql_query($sql);

while($row=mysql_fetch_assoc($result)){

$id=$row['id'];

$str=str_repeat(' ',$num);

echo $str.$id.'=>'.$row['name'].'

---

';

                    display_classify($id,$num+1,$sid);

      }

}

//display_classify();

/*****************************************************/

//The following is the deletion method. Take your time and take a look. The main thing is the order of deletion mentioned below, and pay attention to where you should delete it.

function del_classify($id){

                                                                                                                                                                                                               

$sql="select id,name from wx_kind where pid={$id}";

$result=mysql_query($sql);

while($row=mysql_fetch_assoc($result)){

$id=$row['id'];

del_classify($id);

      }

//Delete operation is executed outside the loop

$sql1="delete from wx_kind where id={$id}";

//Delete directly without any prompt

$result=mysql_query($sql1);

if(!($result && mysql_affected_rows())){

$bool=false;

      }else{

$bool=true;

      }

return $bool;

}

//del_classify(5);

The following is the database code:

--

-- Database: `db_kind`

--

-------------------------------------------------- ----------

--

-- Table structure `wx_kind_dump`

--

CREATE TABLE `wx_kind_dump` (

`id` int(11) NOT NULL auto_increment,

`pid` int(11) NOT NULL,

`name` char(40) NOT NULL,

`path` char(40) NOT NULL,

PRIMARY KEY (`id`)

) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=26;

--

-- Export the data in the table `wx_kind_dump`

--

INSERT INTO `wx_kind_dump` VALUES (1, 0, 'News', '0');

INSERT INTO `wx_kind_dump` VALUES (2, 0, 'Video', '0');

INSERT INTO `wx_kind_dump` VALUES (3, 0, 'picture', '0');

INSERT INTO `wx_kind_dump` VALUES (4, 0, 'Reading', '0');

INSERT INTO `wx_kind_dump` VALUES (5, 1, 'Political News', '0-1');

INSERT INTO `wx_kind_dump` VALUES (6, 1, 'Financial News', '0-1');

INSERT INTO `wx_kind_dump` VALUES (7, 1, 'Entertainment News', '0-1');

INSERT INTO `wx_kind_dump` VALUES (8, 1, 'Sports News', '0-1');

INSERT INTO `wx_kind_dump` VALUES (9, 8, 'Basketball', '0-1-8');

INSERT INTO `wx_kind_dump` VALUES (10, 8, 'football', '0-1-8');

    INSERT INTO `wx_kind_dump` VALUES (11, 8, 'F1', '0-1-8');

    INSERT INTO `wx_kind_dump` VALUES (12, 8, '网球', '0-1-8');

    INSERT INTO `wx_kind_dump` VALUES (13, 9, '国际篮球', '0-1-8-9');

    INSERT INTO `wx_kind_dump` VALUES (14, 9, 'CBA', '0-1-8-9');

    INSERT INTO `wx_kind_dump` VALUES (15, 9, 'CUBA', '0-1-8-9');

    INSERT INTO `wx_kind_dump` VALUES (16, 9, 'NBA', '0-1-8-9');

    INSERT INTO `wx_kind_dump` VALUES (17, 9, 'NCAA', '0-1-8-9');

    INSERT INTO `wx_kind_dump` VALUES (18, 16, '热火', '0-1-8-9-16');

    INSERT INTO `wx_kind_dump` VALUES (19, 16, '湖人', '0-1-8-9-16');

    INSERT INTO `wx_kind_dump` VALUES (20, 16, '雷霆', '0-1-8-9-16');

    INSERT INTO `wx_kind_dump` VALUES (21, 16, '凯尔特人', '0-1-8-9-16');

    INSERT INTO `wx_kind_dump` VALUES (22, 18, 'James', '0-1-8-9-16-18');

    INSERT INTO `wx_kind_dump` VALUES (23, 18, 'Wade', '0-1-8-9-16-18');

    INSERT INTO `wx_kind_dump` VALUES (24, 20, 'KD', '0-1-8-9-16-20');

    INSERT INTO `wx_kind_dump` VALUES (25, 20, 'WS', '0-1-8-9-16-20');

http://www.bkjia.com/PHPjc/477826.htmlwww.bkjia.comtruehttp://www.bkjia.com/PHPjc/477826.htmlTechArticlePHP代码部分： //无限分类-使用路径 //原理：通过路径来进行拆分得到所有想得到的pid以及id,路径是在设计表时的一个字段，包含着从祖先...