Mysql 递归查询

Posted 2020-11-09 喂，wo yang 你啊

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mysql 递归查询

 定义：父子查询： 根据父 id 查询下面所有子节点数据；子父查询： 根据子 id 查询上面所有父节点数据；

1 创建表

DROP TABLE IF EXISTS `shop`;
CREATE TABLE `shop` (
 `shop_id` int(11) NOT \'0\' AUTO_INCREMENT,
 `parent_id` int(11) DEFAULT \'0\',
 `name` varchar(255) DEFAULT \'0\',
 PRIMARY KEY (`shop_id`)
) ENGINE=InnoDB AUTO_INCREMENT=65 DEFAULT CHARSET=utf8;

2 初始化数据：

INSERT INTO `shop` VALUES (\'1\', \'0\', \'总店\';
INSERT INTO `shop` VALUES (\'2\', \'1\', \'分店1\';
INSERT INTO `shop` VALUES (\'3\', \'1\', \'分店2\');
INSERT INTO `shop` VALUES (\'4\', \'1\', \'分店3\');
INSERT INTO `shop` VALUES (\'5\', \'1\', \'分店4\');
INSERT INTO `shop` VALUES (\'6\', \'1\', \'分店5\');
INSERT INTO `shop` VALUES (\'7\', \'1\', \'分店6\');

3 向下递归

利用find_in_set()函数和group_concat()函数实现递归查询：

DROP FUNCTION IF EXISTS queryChildrShop;
CREATE FUNCTION queryChildrShop(shopid INT)
RETURNS VARCHAR(4000)
BEGIN
DECLARE sTemp VARCHAR(4000);
DECLARE sTempChd VARCHAR(4000);

SET sTemp=\'\';
SET sTempChd = CAST(shopid AS CHAR);

WHILE sTempChd IS NOT NULL DO
SET sTemp= CONCAT(sTemp,\',\',sTempChd);
SELECT GROUP_CONCAT(shop_id) INTO sTempChd FROM shop WHERE FIND_IN_SET(parent_Id,sTempChd)>0;
END WHILE;
RETURN sTemp;
END;

4 、调用方法：

select shop_id,parent_id,name from shop where FIND_IN_SET(shop_id,queryChildShop(#{shopId}))

 查询说有父节点为1的门店信息

 

5  向上递归

DROP FUNCTION IF EXISTS queryChildrenAreaInfo1;
CREATE FUNCTION queryChildrenAreaInfo1(areaId INT)
RETURNS VARCHAR(4000)
BEGIN
DECLARE sTemp VARCHAR(4000);
DECLARE sTempChd VARCHAR(4000);

SET sTemp=\'$\';
SET sTempChd = CAST(areaId AS CHAR);
SET sTemp = CONCAT(sTemp,\',\',sTempChd);

SELECT parentId INTO sTempChd FROM t_areainfo WHERE id = sTempChd;
WHILE sTempChd <> 0 DO
SET sTemp = CONCAT(sTemp,\',\',sTempChd);
SELECT parentId INTO sTempChd FROM t_areainfo WHERE id = sTempChd;
END WHILE;
RETURN sTemp;
END;

6、调用方式：

select shop_id,parent_id,name from shop where FIND_IN_SET(shop_id,queryChildrenAreaInfo1(#{shopId}))

查询id为"7"的节点的所有上级节点：