关于多级别菜单栏或者权限系统中部门上下级的树形遍历,oracle中有connect by来实现,mysql没有这样的便捷途径,所以MySQL遍历数据表是我们经常会遇到的头痛问题,下面通过存储过程来实现。
1,建立测试表和数据:
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DROP TABLE IF EXISTS csdn.channel; CREATE TABLE csdn.channel ( id INT (11) NOT NULL AUTO_INCREMENT, cname VARCHAR (200) DEFAULT NULL , parent_id INT (11) DEFAULT NULL , PRIMARY KEY (id) ) ENGINE=INNODB DEFAULT CHARSET=utf8; INSERT INTO channel(id,cname,parent_id) VALUES (13, '首页' ,-1), (14, 'TV580' ,-1), (15, '生活580' ,-1), (16, '左上幻灯片' ,13), (17, '帮忙' ,14), (18, '栏目简介' ,17); DROP TABLE IF EXISTS channel; |
2,利用临时表和递归过程实现树的遍历(mysql的UDF不能递归调用):
2.1,从某节点向下遍历子节点,递归生成临时表数据
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-- pro_cre_childlist DROP PROCEDURE IF EXISTS csdn.pro_cre_childlist CREATE PROCEDURE csdn.pro_cre_childlist( IN rootId INT , IN nDepth INT ) DECLARE done INT DEFAULT 0; DECLARE b INT ; DECLARE cur1 CURSOR FOR SELECT id FROM channel WHERE parent_id=rootId; DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1; SET max_sp_recursion_depth=12; INSERT INTO tmpLst VALUES ( NULL ,rootId,nDepth); OPEN cur1; FETCH cur1 INTO b; WHILE done=0 DO CALL pro_cre_childlist(b,nDepth+1); FETCH cur1 INTO b; END WHILE; CLOSE cur1; |
2.2,从某节点向上追溯根节点,递归生成临时表数据
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-- pro_cre_parentlist DROP PROCEDURE IF EXISTS csdn.pro_cre_parentlist CREATE PROCEDURE csdn.pro_cre_parentlist( IN rootId INT , IN nDepth INT ) BEGIN DECLARE done INT DEFAULT 0; DECLARE b INT ; DECLARE cur1 CURSOR FOR SELECT parent_id FROM channel WHERE id=rootId; DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1; SET max_sp_recursion_depth=12; INSERT INTO tmpLst VALUES ( NULL ,rootId,nDepth); OPEN cur1; FETCH cur1 INTO b; WHILE done=0 DO CALL pro_cre_parentlist(b,nDepth+1); FETCH cur1 INTO b; END WHILE; CLOSE cur1; |
2.3,实现类似Oracle SYS_CONNECT_BY_PATH的功能,递归过程输出某节点id路径
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-- pro_cre_pathlist USE csdn DROP PROCEDURE IF EXISTS pro_cre_pathlist CREATE PROCEDURE pro_cre_pathlist( IN nid INT , IN delimit VARCHAR (10),INOUT pathstr VARCHAR (1000)) BEGIN DECLARE done INT DEFAULT 0; DECLARE parentid INT DEFAULT 0; DECLARE cur1 CURSOR FOR SELECT t.parent_id,CONCAT( CAST (t.parent_id AS CHAR ),delimit,pathstr) FROM channel AS t WHERE t.id = nid; DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1; SET max_sp_recursion_depth=12; OPEN cur1; FETCH cur1 INTO parentid,pathstr; WHILE done=0 DO CALL pro_cre_pathlist(parentid,delimit,pathstr); FETCH cur1 INTO parentid,pathstr; END WHILE; CLOSE cur1; DELIMITER ; |
2.4,递归过程输出某节点name路径
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-- pro_cre_pnlist USE csdn DROP PROCEDURE IF EXISTS pro_cre_pnlist CREATE PROCEDURE pro_cre_pnlist( IN nid INT , IN delimit VARCHAR (10),INOUT pathstr VARCHAR (1000)) BEGIN DECLARE done INT DEFAULT 0; DECLARE parentid INT DEFAULT 0; DECLARE cur1 CURSOR FOR SELECT t.parent_id,CONCAT(t.cname,delimit,pathstr) FROM channel AS t WHERE t.id = nid; DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1; SET max_sp_recursion_depth=12; OPEN cur1; FETCH cur1 INTO parentid,pathstr; WHILE done=0 DO CALL pro_cre_pnlist(parentid,delimit,pathstr); FETCH cur1 INTO parentid,pathstr; END WHILE; CLOSE cur1; DELIMITER ; |
2.5,调用函数输出id路径
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-- fn_tree_path DELIMITER DROP FUNCTION IF EXISTS csdn.fn_tree_path CREATE FUNCTION csdn.fn_tree_path(nid INT ,delimit VARCHAR (10)) RETURNS VARCHAR (2000) CHARSET utf8 BEGIN DECLARE pathid VARCHAR (1000); SET pathid= CAST (nid AS CHAR ); CALL pro_cre_pathlist(nid,delimit,pathid); RETURN pathid; END |
2.6,调用函数输出name路径
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-- fn_tree_pathname -- 调用函数输出name路径 DELIMITER DROP FUNCTION IF EXISTS csdn.fn_tree_pathname CREATE FUNCTION csdn.fn_tree_pathname(nid INT ,delimit VARCHAR (10)) RETURNS VARCHAR (2000) CHARSET utf8 BEGIN DECLARE pathid VARCHAR (1000); SET pathid= '' ; CALL pro_cre_pnlist(nid,delimit,pathid); RETURN pathid; END DELIMITER ; |
2.7,调用过程输出子节点
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-- pro_show_childLst DELIMITER -- 调用过程输出子节点 DROP PROCEDURE IF EXISTS pro_show_childLst CREATE PROCEDURE pro_show_childLst( IN rootId INT ) BEGIN DROP TEMPORARY TABLE IF EXISTS tmpLst; CREATE TEMPORARY TABLE IF NOT EXISTS tmpLst (sno INT PRIMARY KEY AUTO_INCREMENT,id INT ,depth INT ); CALL pro_cre_childlist(rootId,0); SELECT channel.id,CONCAT( SPACE (tmpLst.depth*2), '--' ,channel.cname) NAME ,channel.parent_id,tmpLst.depth,fn_tree_path(channel.id, '/' ) path,fn_tree_pathname(channel.id, '/' ) pathname FROM tmpLst,channel WHERE tmpLst.id=channel.id ORDER BY tmpLst.sno; END |
2.8,调用过程输出父节点
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-- pro_show_parentLst DELIMITER -- 调用过程输出父节点 DROP PROCEDURE IF EXISTS `pro_show_parentLst` CREATE PROCEDURE `pro_show_parentLst`( IN rootId INT ) BEGIN DROP TEMPORARY TABLE IF EXISTS tmpLst; CREATE TEMPORARY TABLE IF NOT EXISTS tmpLst (sno INT PRIMARY KEY AUTO_INCREMENT,id INT ,depth INT ); CALL pro_cre_parentlist(rootId,0); SELECT channel.id,CONCAT( SPACE (tmpLst.depth*2), '--' ,channel.cname) NAME ,channel.parent_id,tmpLst.depth,fn_tree_path(channel.id, '/' ) path,fn_tree_pathname(channel.id, '/' ) pathname FROM tmpLst,channel WHERE tmpLst.id=channel.id ORDER BY tmpLst.sno; END |
3,开始测试:
3.1,从根节点开始显示,显示子节点集合:
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mysql> CALL pro_show_childLst(-1); + ----+-----------------------+-----------+-------+-------------+----------------------------+ | id | NAME | parent_id | depth | path | pathname | + ----+-----------------------+-----------+-------+-------------+----------------------------+ | 13 | --首页 | -1 | 1 | -1/13 | 首页/ | | 16 | --左上幻灯片 | 13 | 2 | -1/13/16 | 首页/左上幻灯片/ | | 14 | --TV580 | -1 | 1 | -1/14 | TV580/ | | 17 | --帮忙 | 14 | 2 | -1/14/17 | TV580/帮忙/ | | 18 | --栏目简介 | 17 | 3 | -1/14/17/18 | TV580/帮忙/栏目简介/ | | 15 | --生活580 | -1 | 1 | -1/15 | 生活580/ | + ----+-----------------------+-----------+-------+-------------+----------------------------+ 6 rows in set (0.05 sec) Query OK, 0 rows affected (0.05 sec) |
3.2,显示首页下面的子节点
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CALL pro_show_childLst(13); mysql> CALL pro_show_childLst(13); + ----+---------------------+-----------+-------+----------+-------------------------+ | id | NAME | parent_id | depth | path | pathname | + ----+---------------------+-----------+-------+----------+-------------------------+ | 13 | --首页 | -1 | 0 | -1/13 | 首页/ | | 16 | --左上幻灯片 | 13 | 1 | -1/13/16 | 首页/左上幻灯片/ | + ----+---------------------+-----------+-------+----------+-------------------------+ 2 rows in set (0.02 sec) Query OK, 0 rows affected (0.02 sec) mysql> |
3.3,显示TV580下面的所有子节点
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CALL pro_show_childLst(14); mysql> CALL pro_show_childLst(14); | id | NAME | parent_id | depth | path | pathname | | 14 | --TV580 | -1 | 0 | -1/14 | TV580/ | | 17 | --帮忙 | 14 | 1 | -1/14/17 | TV580/帮忙/ | | 18 | --栏目简介 | 17 | 2 | -1/14/17/18 | TV580/帮忙/栏目简介/ | 3 rows in set (0.02 sec) Query OK, 0 rows affected (0.02 sec) mysql> |
3.4,“帮忙”节点有一个子节点,显示出来:
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CALL pro_show_childLst(17); mysql> CALL pro_show_childLst(17); | id | NAME | parent_id | depth | path | pathname | | 17 | --帮忙 | 14 | 0 | -1/14/17 | TV580/帮忙/ | | 18 | --栏目简介 | 17 | 1 | -1/14/17/18 | TV580/帮忙/栏目简介/ | 2 rows in set (0.03 sec) Query OK, 0 rows affected (0.03 sec) mysql> |
3.5,“栏目简介”没有子节点,所以只显示最终节点:
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mysql> CALL pro_show_childLst(18); + --| id | NAME | parent_id | depth | path | pathname | | 18 | --栏目简介 | 17 | 0 | -1/14/17/18 | TV580/帮忙/栏目简介/ | 1 row in set (0.36 sec) Query OK, 0 rows affected (0.36 sec) mysql> |
3.6,显示根节点的父节点
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CALL pro_show_parentLst(-1); mysql> CALL pro_show_parentLst(-1); Empty set (0.01 sec) Query OK, 0 rows affected (0.01 sec) mysql> |
3.7,显示“首页”的父节点
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CALL pro_show_parentLst(13); mysql> CALL pro_show_parentLst(13); | id | NAME | parent_id | depth | path | pathname | | 13 | --首页 | -1 | 0 | -1/13 | 首页/ | 1 row in set (0.02 sec) Query OK, 0 rows affected (0.02 sec) mysql> |
3.8,显示“TV580”的父节点,parent_id为-1
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CALL pro_show_parentLst(14); mysql> CALL pro_show_parentLst(14); | id | NAME | parent_id | depth | path | pathname | | 14 | --TV580 | -1 | 0 | -1/14 | TV580/ | 1 row in set (0.02 sec) Query OK, 0 rows affected (0.02 sec) |
3.9,显示“帮忙”节点的父节点
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CALL pro_show_parentLst(17); mysql> CALL pro_show_parentLst(17); | id | NAME | parent_id | depth | path | pathname | | 17 | --帮忙 | 14 | 0 | -1/14/17 | TV580/帮忙/ | | 14 | --TV580 | -1 | 1 | -1/14 | TV580/ | 2 rows in set (0.02 sec) Query OK, 0 rows affected (0.02 sec) mysql> |
3.10,显示最低层节点“栏目简介”的父节点
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CALL pro_show_parentLst(18); mysql> CALL pro_show_parentLst(18); | id | NAME | parent_id | depth | path | pathname | | 18 | --栏目简介 | 17 | 0 | -1/14/17/18 | TV580/帮忙/栏目简介/ | | 17 | --帮忙 | 14 | 1 | -1/14/17 | TV580/帮忙/ | | 14 | --TV580 | -1 | 2 | -1/14 | TV580/ | 3 rows in set (0.02 sec) Query OK, 0 rows affected (0.02 sec) mysql> |
以上所述是小编给大家介绍的在Mysql数据库里通过存储过程实现树形的遍历,希望对大家有所帮助,如果大家有任何疑问请给我留言,小编会及时回复大家的。在此也非常感谢大家对服务器之家网站的支持!