Thinkphp achieves unlimited classification

The above is 1. database Design 2. the data in the added database is parsed as follows: the parent class id of the self-incrementing idpid column in the cid column. The id is 0, indicating the name of the cat_name column in the top-level column p...

The above is

1. database design

2. the added database data is shown in figure

Resolution: cid column auto-increment id

The parent class id of the pid column. if the id is 0, it indicates that it is a top-level column.

Cat_name topic name

Path indicates the hierarchical relationship of a topic.

The implementation results are mainly used:

A mysql function concat (): returns the string generated by the connection parameter.

1. classification display method of the controller

1. Public function fenlei (){
2. $ Cate = M ('Category ');
3. $ List = $ cate-> field ("cid, cat_name, pid, path, concat (path, '-', cid) as bpath")-> order ('bpath ') -> select ();
4. Foreach ($ list as $ key => $ value ){
5. $ List [$ key] ['count'] = count (explode ('-', $ value ['bpath']);
6. }
7. $ This-> assign ('alist', $ list );
8. $ This-> display ();
9. }

2. how to add a controller category

1. Public function addCat (){
2. $ Cate = D ('Category ');
3. If ($ cate-> create ()){
4. If ($ cate-> add ()){
5. $ This-> redirect ('/Test/fenlei ');
6. } Else {
7. $ This-> error ('add topic failed ');
8. }
9. } Else {
10. $ This-> error ($ cate-> getError ());
11. }
12. }

3. topic model

2. Class CategoryModel extends Model {
3. Protected $ _ auto = array (
4. Array ('path', 'tclm', 3, 'callback '),
5. );
6. Function tclm (){
7. $ Pid = isset ($ _ POST ['pid'])? (Int) $ _ POST ['pid']: 0;
8. // Echo ($ pid );
9. If ($ pid = 0 ){
10. $ Data = 0;
11. } Else {
12. $ List = $ this-> where ("cid = $ pid")-> find ();
13. $ Data = $ list ['path']. '-'. $ list ['CID']; // The path of the subclass adds the cid of the parent class to the path of the parent class.
14. }
15. Return $ data;
16. }
17. }
18. ?>

4. main html code

1.  
2.  
3.