我试图围绕查询具有层次结构类别数据(用于cms)的表进行打包,该表还与我的帖子数据和多对多类型关系绑定我的post2cat表。具体来说,我的问题是,如何获取属于某个特定类别ID的任何子类别的所有帖子(不限于直接后裔,但可以是n级)?这里是我的表:需要分层Mysql查询的帮助
'类' 表:
+-----------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------+-------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(45) | YES | | NULL | |
| parent_id | int(11) | YES | MUL | 0 | |
+-----------+-------------+------+-----+---------+----------------+
3 rows in set (0.00 sec)
'post2cat' 表:
+---------+---------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+---------+---------+------+-----+---------+-------+
| post_id | int(11) | NO | MUL | NULL | |
| cat_id | int(11) | NO | MUL | NULL | |
+---------+---------+------+-----+---------+-------+
2 rows in set (0.00 sec)
'帖子' 表:
+---------------+--------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------------+--------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| title | varchar(256) | NO | | NULL | |
| content | text | NO | | NULL | |
| end_date | datetime | NO | | NULL | |
| format_id | int(11) | NO | | NULL | |
| featured | int(1) | NO | | NULL | |
| status | int(3) | NO | | NULL | |
| publish_date | datetime | NO | | NULL | |
| date_created | datetime | NO | | NULL | |
| date_modified | datetime | NO | | NULL | |
+---------------+--------------+------+-----+---------+----------------+
POST_ID名称描述
post2cat
你'类别'表是一个邻接表模型。使用MySQL会话变量来遍历树。我关于SQL中的分层数据的问题涵盖了更多关于这个一般问题的内容:http://stackoverflow.com/questions/4048151/what-are-the-options-for-storing-hierarchical-data-in-a-relational-数据库 – orangepips 2011-04-19 14:38:08