MySQL存储过程实现Oracle邻接模型树形处理的方法实例
发布:smiling 来源: PHP粉丝网 添加日期:2015-04-20 15:10:50 浏览: 评论:0
项目需求用到了邻接模型,但是是采用开源的Mysql,而Mysql没有这个功能,Oracle数据库提供了现在的分析方法 connect by 处理邻接模型,不过mysql支持存储过程,可以建立存储过程实现Oracle的分析功能.
数据库对层次结构的处理模型有好多种,可以根据自己的需求来设计模型,当然最简单的也是最容易设计的模型就是所谓的邻接模型,在这方面,其他数据库比如Oracle 提供了现成的分析方法 connect by,而MySQL在这方面就显得有些薄弱了,不过可以用MySQL的存储过程实现ORACLE类似的分析功能.
这样,先来创建一个简单的数表,代码如下:
- create table country ( id number(2) not null, name varchar(60) not null);
- create table country_relation (id number(2), parentid number(2));
- create table country_relation (id number(2), parentid number(2));
插入一些数据,代码如下:
- -- Table country.
- insert into country (id,name) values (0,'Earth');
- insert into country (id,name) values (2,'North America');
- insert into country (id,name) values (3,'South America');
- insert into country (id,name) values (4,'Europe');
- insert into country (id,name) values (5,'Asia');
- insert into country (id,name) values (6,'Africa');
- insert into country (id,name) values (7,'Australia');
- insert into country (id,name) values (8,'Canada');
- insert into country (id,name) values (9,'Central America');
- insert into country (id,name) values (10,'Island Nations');
- insert into country (id,name) values (11,'United States');
- insert into country (id,name) values (12,'Alabama');
- insert into country (id,name) values (13,'Alaska');
- insert into country (id,name) values (14,'Arizona');
- insert into country (id,name) values (15,'Arkansas');
- insert into country (id,name) values (16,'California');
- -- Table country_relation.
- insert into country_relation (id,parentid) values (0,NULL);
- insert into country_relation (id,parentid) values (2,0);
- insert into country_relation (id,parentid) values (3,0);
- insert into country_relation (id,parentid) values (4,0);
- insert into country_relation (id,parentid) values (5,0);
- insert into country_relation (id,parentid) values (6,0);
- insert into country_relation (id,parentid) values (7,0);
- insert into country_relation (id,parentid) values (8,2);
- insert into country_relation (id,parentid) values (9,2);
- insert into country_relation (id,parentid) values (10,2);
- insert into country_relation (id,parentid) values (11,2);
- insert into country_relation (id,parentid) values (12,11);
- insert into country_relation (id,parentid) values (13,11);
- insert into country_relation (id,parentid) values (14,11);
- insert into country_relation (id,parentid) values (15,11);
- insert into country_relation (id,parentid) values (16,11);
在Oracle 里面,对这些操作就比较简单了,都是系统提供的,比如下面四种情形.
1).查看深度,代码如下:
- select max(level) "level" from COUNTRY_RELATION a start with a.parentid is NULL
- connect by PRIOR a.id = a.PARENTID
- order by level;
- level
- ----------
- 4
- --已用时间: 00: 00: 00.03
2).查看叶子节点,代码如下:
- select name from
- (
- select b.name, connect_by_isleaf "isleaf"
- from COUNTRY_RELATION a inner join country b on (a.id = b.id)
- start with a.parentid is NULL connect by prior a.id = a.PARENTID
- ) T where T."isleaf" = 1;
- NAME
- --------------------------------------------------
- Canada
- Central America
- Island Nations
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- South America
- Europe
- Asia
- Africa
- Australia
- --已选择13行。
- --已用时间: 00: 00: 00.01
3).查看ROOT节点,代码如下:
- select connect_by_root b.name
- from COUNTRY_RELATION a inner join country b on (a.id = b.id)
- start with a.parentid is NULL connect by a.id = a.PARENTID
- --phpfensi.com
- CONNECT_BY_ROOTB.NAME
- --------------------------------------------------
- Earth
- --已用时间: 00: 00: 00.01
4).查看路径,代码如下:
- select sys_connect_by_path(b.name,'/') "path"
- from COUNTRY_RELATION a inner join country b on (a.id = b.id)
- start with a.parentid is NULL connect by prior a.id = a.PARENTID
- order by level,a.id;
- path
- --------------------------------------------------
- /Earth
- /Earth/North America
- /Earth/South America
- /Earth/Europe
- /Earth/Asia
- /Earth/Africa
- /Earth/Australia
- /Earth/North America/Canada
- /Earth/North America/Central America
- /Earth/North America/Island Nations
- /Earth/North America/United States
- /Earth/North America/United States/Alabama
- /Earth/North America/United States/Alaska
- /Earth/North America/United States/Arizona
- /Earth/North America/United States/Arkansas
- /Earth/North America/United States/California
- --已选择16行。
- --已用时间: 00: 00: 00.01
接下来我们看看在MySQL 里面如何实现上面四种情形,前三种都比较简单,可以很容易写出SQL.
1)查看深度,代码如下:
- mysql> SELECT COUNT(DISTINCT IFNULL(parentid,-1)) AS LEVEL FROM country_relation
- ;
- +-------+
- | LEVEL |
- +-------+
- | 4 |
- +-------+
- 1 row in set (0.00 sec)
2)查看ROOT节点,代码如下:
- mysql> SELECT b.`name` AS root_node FROM
- -> (
- -> SELECT id FROM country_relation WHERE parentid IS NULL
- -> ) AS a, country AS b WHERE a.id = b.id;
- +-----------+
- | root_node |
- +-----------+
- | Earth |
- +-----------+
- 1 row in set (0.00 sec)
3).查看叶子节点,代码如下:
- mysql> SELECT b.`name` AS leaf_node FROM
- -> (
- -> SELECT id FROM country_relation WHERE id NOT IN (SELECT IFNULL(parentid,
- -1) FROM country_relation)
- -> ) AS a, country AS b WHERE a.id = b.id;
- +-----------------+
- | leaf_node |
- +-----------------+
- | South America |
- | Europe |
- | Asia |
- | Africa |
- | Australia |
- | Canada |
- | Central America |
- | Island Nations |
- | Alabama |
- | Alaska |
- | Arizona |
- | Arkansas |
- | California |
- +-----------------+
- 13 rows in set (0.00 sec)
- mysql>
4)查看路径
这一块没有简单的SQL实现,不过可以用MySQL的存储过程来实现同样的功能,存储过程代码如下:
- DELIMITER $$
- USE `t_girl`$$
- DROP PROCEDURE IF EXISTS `sp_show_list`$$
- CREATE DEFINER=`root`@`localhost` PROCEDURE `sp_show_list`()
- BEGIN
- -- Created by ytt 2014/11/04.
- -- Is equal to oracle's connect by syntax.
- -- Body.
- DROP TABLE IF EXISTS tmp_country_list;
- CREATE TEMPORARY TABLE tmp_country_list (node_level INT UNSIGNED NOT NULL, node_path VARCHAR(1000) NOT NULL);
- -- Get the root node.
- INSERT INTO tmp_country_list SELECT 1, CONCAT('/',id) FROM country_relation WHERE parentid IS NULL;
- -- Loop within all parent node.
- cursor1:BEGIN
- DECLARE done1 INT DEFAULT 0;
- DECLARE i1 INT DEFAULT 1;
- DECLARE v_parentid INT DEFAULT -1;
- DECLARE v_node_path VARCHAR(1000) DEFAULT '';
- DECLARE cr1 CURSOR FOR SELECT parentid FROM country_relation WHERE parentid IS NOT NULL GROUP BY parentid ORDER BY parentid ASC;
- DECLARE CONTINUE HANDLER FOR NOT FOUND SET done1 = 1;
- OPEN cr1;
- loop1:LOOP
- FETCH cr1 INTO v_parentid;
- IF done1 = 1 THEN
- LEAVE loop1;
- END IF;
- SET i1 = i1 + 1;
- label_path:BEGIN
- DECLARE done2 INT DEFAULT 0;
- DECLARE CONTINUE HANDLER FOR NOT FOUND SET done2 = 1;
- -- Get the upper path.
- SELECT node_path FROM tmp_country_list WHERE node_level = i1 - 1 AND LOCATE(v_parentid,node_path) > 0 INTO v_node_path;
- -- Escape the outer not found exception.
- IF done2 = 1 THEN
- SET done2 = 0;
- END IF;
- INSERT INTO tmp_country_list
- SELECT i1,CONCAT(IFNULL(v_node_path,''),'/',id) FROM country_relation WHERE parentid = v_parentid;
- END;
- END LOOP;
- CLOSE cr1;
- END;
- -- Update node's id to its real name.
- update_name_label:BEGIN
- DECLARE cnt INT DEFAULT 0;
- DECLARE i2 INT DEFAULT 0;
- SELECT MAX(node_level) FROM tmp_country_list INTO cnt;
- WHILE i2 < cnt
- DO
- UPDATE tmp_country_list AS a, country AS b
- SET a.node_path = REPLACE(a.node_path,CONCAT('/',b.id),CONCAT('/',b.name))
- WHERE LOCATE(CONCAT('/',b.id),a.node_path) > 0;
- SET i2 = i2 + 1;
- END WHILE;
- END;
- SELECT node_path FROM tmp_country_list;
- END$$
- DELIMITER ;
调用结果,代码如下:
- mysql> CALL sp_show_list();
- +-----------------------------------------------+
- | node_path |
- +-----------------------------------------------+
- | /Earth |
- | /Earth/North America |
- | /Earth/South America |
- | /Earth/Europe |
- | /Earth/Asia |
- | /Earth/Africa |
- | /Earth/Australia |
- | /Earth/North America/Canada |
- | /Earth/North America/Central America |
- | /Earth/North America/Island Nations |
- | /Earth/North America/United States |
- | /Earth/North America/United States/Alabama |
- | /Earth/North America/United States/Alaska |
- | /Earth/North America/United States/Arizona |
- | /Earth/North America/United States/Arkansas |
- | /Earth/North America/United States/California |
- +-----------------------------------------------+
- 16 rows in set (0.04 sec)
- Query OK, 0 rows affected (0.08 sec)
- mysql>
Tags: MySQL存储过程 Oracle邻接模型
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