Php unlimited classifier _ PHP Tutorial-php Tutorial

Php unlimited classification program. In the past, I often introduced the issue of infinite classification. In most cases, we use php recursion. the infinite classification introduced today does not require recursion, the method is very simple. we need to introduce the infinite classification problem frequently before. In most cases, we use php recursion. the infinite classification introduced today does not require recursion, the method is simple. if you need it, you can refer to it.

The code is as follows:

////////////// ///// Database design and example of unlimited classification ////////////// Mysql> create database db_kind; Query OK, 1 row affected Mysql> use db_kind; Database changed Mysql> create table tb_kind ( -> Id int not null auto_increment primary key, -> Pid int, -> Path varchar (200) -> ); Query OK, 0 rows affected Mysql> insert into tb_kind values (null, "news", 0, 0 ); Query OK, 1 row affected Mysql> insert into tb_kind values (null, "video", 0, 0 ); Query OK, 1 row affected Mysql> insert into tb_kind values (null, "image", 0, 0 ); Query OK, 1 row affected Mysql> insert into tb_kind values (null, "blog", 0, 0 ); Query OK, 1 row affected Mysql> insert into tb_kind values (null, "Sports News", 1, "0-1 "); Query OK, 1 row affected Mysql> insert into tb_kind values (null, "Entertainment News", 1, "0-1 "); Query OK, 1 row affected Mysql> insert into tb_kind values (null, "Financial News", 1, "0-1 "); Query OK, 1 row affected Mysql> select * from db_kind; ERROR 1146: Table 'DB _ kind. db_kind 'doesnot exist Mysql> select * from tb _ Kind; + ---- + ---------- + ----- + ------ + | Id | pname | pid | path | + ---- + ---------- + ----- + ------ + | 1 | news | 0 | 0 | | 2 | video | 0 | 0 | | 3 | Image | 0 | 0 | | 4 | blog | 0 | 0 | | 5 | sports news | 1 | 0-1 | | 6 | entertainment news | 1 | 0-1 | | 7 | financial news | 1 | 0-1 | + ---- + ---------- + ----- + ------ + 7 rows in set Mysql> insert into tb_kind values (null, "Basketball News", 5, "0-1-5 "); Query OK, 1 row affected Mysql> insert into tb_kind values (null, "Football News", 5, "0-1-5 "); Query OK, 1 row affected Mysql> select * from tb_kind; + ---- + ---------- + ----- + ------- + | Id | pname | pid | path | + ---- + ---------- + ----- + ------- + | 1 | news | 0 | 0 | | 2 | video | 0 | 0 | | 3 | Image | 0 | 0 | | 4 | blog | 0 | 0 | | 5 | sports news | 1 | 0-1 | | 6 | entertainment news | 1 | 0-1 | | 7 | financial news | 1 | 0-1 | | 8 | basketball news | 5 | 0-1-5 | | 9 | Football News | 5 | 0-1-5 | + ---- + ---------- + ----- + ------- + 9 rows in set Mysql> insert into tb_kind values (null, "NBA", 8, "0-1-5-8 "); Query OK, 1 row affected Mysql> insert into tb_kind values (null, "CBA", 8, "0-1-5-8 "); Query OK, 1 row affected Mysql> select * from tb_kind; + ---- + ---------- + ----- + --------- + | Id | pname | pid | path | + ---- + ---------- + ----- + --------- + | 1 | news | 0 | 0 | | 2 | video | 0 | 0 | | 3 | Image | 0 | 0 | | 4 | blog | 0 | 0 | | 5 | sports news | 1 | 0-1 | | 6 | entertainment news | 1 | 0-1 | | 7 | financial news | 1 | 0-1 | | 8 | basketball news | 5 | 0-1-5 | | 9 | Football News | 5 | 0-1-5 | | 10 | NBA | 8 | 0-1-5-8 | | 11 | CBA | 8 | 0-1-5-8 | + ---- + ---------- + ----- + --------- + 11 rows in set Mysql> select concat (path, "-", id) from tb_kind; + --------------------- + | Concat (path, "-", id) | + --------------------- + | 0-1 | | 0-2 | | 0-3 | | 0-4 | | 0-1-5 | | 0-1-6 | | 0-1-7 | | 0-1-5-8 | | 0-1-5-9 | | 0-1-5-8-10 | | 0-1-5-8-11 | + --------------------- + 11 rows in set Mysql> select concat (path, "-", id) from tb_kind; + --------------------- + | Concat (path, "-", id) | + --------------------- + | 0-1 | | 0-2 | | 0-3 | | 0-4 | | 0-1-5 | | 0-1-6 | | 0-1-7 | | 0-1-5-8 | | 0-1-5-9 | | 0-1-5-8-10 | | 0-1-5-8-11 | + --------------------- + 11 rows in set Mysql> select concat (path, "-", id) as abs from tb_kind order by abs. path; ERROR 1054: Unknown column 'abs. path' in 'Order clause' Mysql> select concat (path, "-", id) as abs from tb_kind order by abs + ------------ + | Abs | + ------------ + | 0-1 | | 0-1-5 | | 0-1-5-8 | | 0-1-5-8-10 | | 0-1-5-8-11 | | 0-1-5-9 | | 0-1-6 | | 0-1-7 | | 0-2 | | 0-3 | | 0-4 | + ------------ + 11 rows in set Mysql> select concat (path, "-", id) as, id, name, path abs from tb_kind order by abs; ERROR 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'id, name, path abs from tb_kind order by abs 'at line 1 Mysql> select concat (path, "-", id) as abs, Id, pname, path abs from tb_kind order by abs; + ------------ + ---- + ---------- + --------- + | Abs | id | pname | abs | + ------------ + ---- + ---------- + --------- + | 0-1 | 1 | news | 0 | | 0-1-5 | 5 | sports news | 0-1 | | 0-1-5-8 | 8 | basketball news | 0-1-5 | | 0-1-5-8-10 | 10 | NBA | 0-1-5-8 | | 0-1-5-8-11 | 11 | CBA | 0-1-5-8 | | 0-1-5-9 | 9 | Football News | 0-1-5 | | 0-1-6 | 6 | entertainment news | 0-1 | | 0-1-7 | 7 | financial news | 0-1 | | 0-2 | 2 | video | 0 | | 0-3 | 3 | Image | 0 | | 0-4 | 4 | blog | 0 | + ------------ + ---- + ---------- + --------- + 11 rows in set Mysql> Php classification source code Untitled Document $ Conn = mysql_connect ("localhost", "root", "root "); Mysql_select_db ("db_kind "); Mysql_query ("set names utf8 "); $ SQL = "select concat (path, '-', id) as abspath, id, pname, path from tb_kind order by abspath "; $ Rs = mysql_query ($ SQL ); While ($ result = mysql_fetch_assoc ($ rs )){ $ Num = count (explode ("-", $ result [path])-1; $ New_str = str_repeat ("---", $ num ); Echo $ new_str. $ result [pname]; Echo" "; } $ Str = str_repeat ("=", 10 ); Echo $ str; $ Num = count (explode ("-", "0-1-5-8")-1; Echo $ num; ?>

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