MySQL 中的树形数据处理示例

创建测试表

CREATE TABLE `areatest` ( `id` int(11) NOT NULL AUTO_INCREMENT, `parent_id` int(11) NOT NULL DEFAULT '0' COMMENT '父ID', `order_id` int(11) NOT NULL DEFAULT '0' COMMENT '排序ID', `name` varchar(50) NOT NULL COMMENT '名称', PRIMARY KEY (`id`) ) ENGINE=MyISAM AUTO_INCREMENT=0 DEFAULT CHARSET=utf8 COMMENT='地区'; insert into `areatest` values (1,0,1,'北京'),(2,0,3,'江西'),(3,0,2,'上海'),(4,2,1,'南昌'),(5,2,2,'九江'),(6,4,1,'永修'),(7,4,2,'星子'),(8,2,3,'赣州');

 

 

创建树形层次分析存储过程

DELIMITER $$ DROP PROCEDURE IF EXISTS `sp_areatest_child_nodes`$$ /*获取指定 父ID 树形层次数据放到 child_nodes 临时表*/ CREATE PROCEDURE `sp_areatest_child_nodes`(IN $parent_id INT/*父ID*/) BEGIN DECLARE LEVEL SMALLINT DEFAULT 0;/*层次*/ DECLARE cou INT DEFAULT 0; DROP TABLE IF EXISTS child_nodes_temp;/*单层次临时表*/ DROP TABLE IF EXISTS child_nodes;/*层次临时表*/ CREATE TEMPORARY TABLE child_nodes_temp(`id` INT,`level` INT,`order_id` VARCHAR(1000)) DEFAULT CHARSET=utf8; CREATE TEMPORARY TABLE child_nodes(`id` INT,`level` INT,`order_id` VARCHAR(1000)) DEFAULT CHARSET=utf8; INSERT INTO child_nodes_temp SELECT `id`,LEVEL,CAST(RIGHT(100+`order_id`,2) AS CHAR) FROM `areatest` WHERE `parent_id`=$parent_id; SELECT ROW_COUNT() INTO cou; INSERT INTO child_nodes SELECT * FROM child_nodes_temp; WHILE cou>0 DO SET LEVEL=LEVEL+1; TRUNCATE TABLE child_nodes_temp; INSERT INTO child_nodes_temp SELECT a.`id`,LEVEL,CONCAT(b.order_id,CAST(RIGHT(100+a.`order_id`,2) AS CHAR)) FROM `areatest` a,child_nodes b WHERE a.`parent_id`=b.`id` AND b.`level`=LEVEL-1; SELECT ROW_COUNT() INTO cou; INSERT INTO child_nodes SELECT * FROM child_nodes_temp; END WHILE; DROP TABLE child_nodes_temp; END$$ DELIMITER ;

 

创建树形数据查询存储过程

DELIMITER $$ DROP PROCEDURE IF EXISTS `sp_areatest_tree`$$ /*获取指定 父ID 树形数据*/ CREATE PROCEDURE `sp_areatest_tree`(IN $parent_id INT/*父ID*/) BEGIN CALL sp_areatest_child_nodes($parent_id); SELECT a.id,CASE b.parent_id WHEN 0 THEN b.name ELSE CONCAT(SPACE(a.level*2),'|-',b.name) END AS `name` FROM child_nodes a INNER JOIN `areatest` b ON a.id=b.id ORDER BY a.order_id; DROP TABLE child_nodes; END$$ DELIMITER ;

 

 

测试1

CALL sp_areatest_tree(0);

 

测试2

CALL sp_areatest_tree(2);