yii或mysql或php获取所有子类别树

Question

mysql中的表：

id | name        | prent
----------------------------
1  | cat1        | 0
2  | cat1.1      | 1
3  | cat2.1      | 1
4  | cat11.2     | 2
5  | cat11.4     | 4
6  | cat1        | 0

我想在选择id 1（cat1）时，我想获得所有子类别ID。结果：＆＃34; 2,3,4,5＆＃34;

Answer 1

如果需要选择所有子类别添加列路径

id | name        | parent | path
-----------------------------------
1  | cat1        | 0      | 0-1
2  | cat1.1      | 1      | 0-1-2
3  | cat2.1      | 1      | 0-1-3
4  | cat11.2     | 2      | 0-1-2-4
5  | cat11.4     | 4      | 0-1-2-4-5
6  | cat1        | 0      | 0-6

和查询：

SELECT * FROM tree WHERE path LIKE '0-1-%' ORDER BY path ASC;

path_parent = concat('0','-',id_parent)

path_child = concat('path_parent', '-', 'id_child')