次のコードは、対応するデータベースを作成する SQL コードです:
コードをコピーします コードは次のとおりです:
//////////////
//////无限分类的数据库设计及样例
//////////////
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,"新闻",0,0);
Query OK, 1 row affected
mysql> insert into tb_kind values(null,"视频",0,0);
Query OK, 1 row affected
mysql> insert into tb_kind values(null,"图片",0,0);
Query OK, 1 row affected
mysql> insert into tb_kind values(null,"博客",0,0);
Query OK, 1 row affected
mysql> insert into tb_kind values(null,"体育新闻",1,"0-1");
Query OK, 1 row affected
mysql> insert into tb_kind values(null,"娱乐新闻",1,"0-1");
Query OK, 1 row affected
mysql> insert into tb_kind values(null,"财经新闻",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 | 新闻 | 0 | 0 |
| 2 | 视频 | 0 | 0 |
| 3 | 图片 | 0 | 0 |
| 4 | 博客 | 0 | 0 |
| 5 | 体育新闻 | 1 | 0-1 |
| 6 | 娱乐新闻 | 1 | 0-1 |
| 7 | 财经新闻 | 1 | 0-1 |
+----+----------+-----+------+
7 rows in set
mysql> insert into tb_kind values(null,"篮球新闻",5,"0-1-5");
Query OK, 1 row affected
mysql> insert into tb_kind values(null,"足球新闻",5,"0-1-5");
Query OK, 1 row affected
mysql> select * from tb_kind;
+----+----------+-----+-------+
| id | pname | pid | path |
+----+----------+-----+-------+
| 1 | 新闻 | 0 | 0 |
| 2 | 视频 | 0 | 0 |
| 3 | 图片 | 0 | 0 |
| 4 | 博客 | 0 | 0 |
| 5 | 体育新闻 | 1 | 0-1 |
| 6 | 娱乐新闻 | 1 | 0-1 |
| 7 | 财经新闻 | 1 | 0-1 |
| 8 | 篮球新闻 | 5 | 0-1-5 |
| 9 | 足球新闻 | 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 | 新闻 | 0 | 0 |
| 2 | 视频 | 0 | 0 |
| 3 | 图片 | 0 | 0 |
| 4 | 博客 | 0 | 0 |
| 5 | 体育新闻 | 1 | 0-1 |
| 6 | 娱乐新闻 | 1 | 0-1 |
| 7 | 财经新闻 | 1 | 0-1 |
| 8 | 篮球新闻 | 5 | 0-1-5 |
| 9 | 足球新闻 | 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 | 新闻 | 0 |
| 0-1-5 | 5 | 体育新闻 | 0-1 |
| 0-1-5-8 | 8 | 篮球新闻 | 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 | 足球新闻 | 0-1-5 |
| 0-1-6 | 6 | 娱乐新闻 | 0-1 |
| 0-1-7 | 0-2 | 写真 0 | 0-4 | 0 |
+-----------+------+----------+---------+
セット内の 11 行
mysql> ;
以下は php ソース ファイルです:
コードをコピーします
コードは次のとおりです:
無題のドキュメント
$conn=mysql_connect ("localhost","root","root");
mysql_select_db("db_kind");
$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 [パス]))-1;
$new_str=str_repeat("---",$num);
echo $new_str.$result[pname];
echo "
";
}
$str= str_repeat("=,10);
$num=count("-","0-1-5-8")-1; ?> >
実際、上記のコードの途中にスペースを入れた場合の効果は非常に優れています。エディターの問題により、組版が混乱します。
http://www.bkjia.com/PHPjc/324355.html
www.bkjia.com
true
http://www.bkjia.com/PHPjc/324355.html
技術記事
次のコードは、対応するデータベースを作成する SQL コードです。次のようにコードをコピーします。 /////////////// //////無限に分類されたデータベースの設計と例// //// //////// mysql データベースを作成します...