mysql如何实现递归查询

MysqL实现递归查询的方法：首先创建表，并初始化数据；然后向下递归，利用【find_in_set()】函数和【group_concat()】函数实现递归查询。

本教程操作环境：windows7系统、MysqL8.0.22版、thinkpad t480电脑。

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MysqL实现递归查询的方法：

1、创建表

DROP TABLE IF EXISTS `t_areainfo`;
CREATE TABLE `t_areainfo` (
 `id` int(11) NOT '0' AUTO_INCREMENT,
 `level` int(11) DEFAULT '0',
 `name` varchar(255) DEFAULT '0',
 `parentId` int(11) DEFAULT '0',
 `status` int(11) DEFAULT '0',
 PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=65 DEFAULT CHARSET=utf8;

2、初始数据

INSERT INTO `t_areainfo` VALUES ('1', '0', '中国', '0', '0');
INSERT INTO `t_areainfo` VALUES ('2', '0', '华北区', '1', '0');
INSERT INTO `t_areainfo` VALUES ('3', '0', '华南区', '1', '0');
INSERT INTO `t_areainfo` VALUES ('4', '0', '北京', '2', '0');
INSERT INTO `t_areainfo` VALUES ('5', '0', '海淀区', '4', '0');
INSERT INTO `t_areainfo` VALUES ('6', '0', '丰台区', '4', '0');
INSERT INTO `t_areainfo` VALUES ('7', '0', '朝阳区', '4', '0');
INSERT INTO `t_areainfo` VALUES ('8', '0', '北京XX区1', '4', '0');
INSERT INTO `t_areainfo` VALUES ('9', '0', '北京XX区2', '4', '0');
INSERT INTO `t_areainfo` VALUES ('10', '0', '北京XX区3', '4', '0');
INSERT INTO `t_areainfo` VALUES ('11', '0', '北京XX区4', '4', '0');
INSERT INTO `t_areainfo` VALUES ('12', '0', '北京XX区5', '4', '0');
INSERT INTO `t_areainfo` VALUES ('13', '0', '北京XX区6', '4', '0');
INSERT INTO `t_areainfo` VALUES ('14', '0', '北京XX区7', '4', '0');
INSERT INTO `t_areainfo` VALUES ('15', '0', '北京XX区8', '4', '0');
INSERT INTO `t_areainfo` VALUES ('16', '0', '北京XX区9', '4', '0');
INSERT INTO `t_areainfo` VALUES ('17', '0', '北京XX区10', '4', '0');
INSERT INTO `t_areainfo` VALUES ('18', '0', '北京XX区11', '4', '0');
INSERT INTO `t_areainfo` VALUES ('19', '0', '北京XX区12', '4', '0');
INSERT INTO `t_areainfo` VALUES ('20', '0', '北京XX区13', '4', '0');
INSERT INTO `t_areainfo` VALUES ('21', '0', '北京XX区14', '4', '0');
INSERT INTO `t_areainfo` VALUES ('22', '0', '北京XX区15', '4', '0');
INSERT INTO `t_areainfo` VALUES ('23', '0', '北京XX区16', '4', '0');
INSERT INTO `t_areainfo` VALUES ('24', '0', '北京XX区17', '4', '0');
INSERT INTO `t_areainfo` VALUES ('25', '0', '北京XX区18', '4', '0');
INSERT INTO `t_areainfo` VALUES ('26', '0', '北京XX区19', '4', '0');
INSERT INTO `t_areainfo` VALUES ('27', '0', '北京XX区1', '4', '0');
INSERT INTO `t_areainfo` VALUES ('28', '0', '北京XX区2', '4', '0');
INSERT INTO `t_areainfo` VALUES ('29', '0', '北京XX区3', '4', '0');
INSERT INTO `t_areainfo` VALUES ('30', '0', '北京XX区4', '4', '0');
INSERT INTO `t_areainfo` VALUES ('31', '0', '北京XX区5', '4', '0');
INSERT INTO `t_areainfo` VALUES ('32', '0', '北京XX区6', '4', '0');
INSERT INTO `t_areainfo` VALUES ('33', '0', '北京XX区7', '4', '0');
INSERT INTO `t_areainfo` VALUES ('34', '0', '北京XX区8', '4', '0');
INSERT INTO `t_areainfo` VALUES ('35', '0', '北京XX区9', '4', '0');
INSERT INTO `t_areainfo` VALUES ('36', '0', '北京XX区10', '4', '0');
INSERT INTO `t_areainfo` VALUES ('37', '0', '北京XX区11', '4', '0');
INSERT INTO `t_areainfo` VALUES ('38', '0', '北京XX区12', '4', '0');
INSERT INTO `t_areainfo` VALUES ('39', '0', '北京XX区13', '4', '0');
INSERT INTO `t_areainfo` VALUES ('40', '0', '北京XX区14', '4', '0');
INSERT INTO `t_areainfo` VALUES ('41', '0', '北京XX区15', '4', '0');
INSERT INTO `t_areainfo` VALUES ('42', '0', '北京XX区16', '4', '0');
INSERT INTO `t_areainfo` VALUES ('43', '0', '北京XX区17', '4', '0');
INSERT INTO `t_areainfo` VALUES ('44', '0', '北京XX区18', '4', '0');
INSERT INTO `t_areainfo` VALUES ('45', '0', '北京XX区19', '4', '0');
INSERT INTO `t_areainfo` VALUES ('46', '0', 'xx省1', '1', '0');
INSERT INTO `t_areainfo` VALUES ('47', '0', 'xx省2', '1', '0');
INSERT INTO `t_areainfo` VALUES ('48', '0', 'xx省3', '1', '0');
INSERT INTO `t_areainfo` VALUES ('49', '0', 'xx省4', '1', '0');
INSERT INTO `t_areainfo` VALUES ('50', '0', 'xx省5', '1', '0');
INSERT INTO `t_areainfo` VALUES ('51', '0', 'xx省6', '1', '0');
INSERT INTO `t_areainfo` VALUES ('52', '0', 'xx省7', '1', '0');
INSERT INTO `t_areainfo` VALUES ('53', '0', 'xx省8', '1', '0');
INSERT INTO `t_areainfo` VALUES ('54', '0', 'xx省9', '1', '0');
INSERT INTO `t_areainfo` VALUES ('55', '0', 'xx省10', '1', '0');
INSERT INTO `t_areainfo` VALUES ('56', '0', 'xx省11', '1', '0');
INSERT INTO `t_areainfo` VALUES ('57', '0', 'xx省12', '1', '0');
INSERT INTO `t_areainfo` VALUES ('58', '0', 'xx省13', '1', '0');
INSERT INTO `t_areainfo` VALUES ('59', '0', 'xx省14', '1', '0');
INSERT INTO `t_areainfo` VALUES ('60', '0', 'xx省15', '1', '0');
INSERT INTO `t_areainfo` VALUES ('61', '0', 'xx省16', '1', '0');
INSERT INTO `t_areainfo` VALUES ('62', '0', 'xx省17', '1', '0');
INSERT INTO `t_areainfo` VALUES ('63', '0', 'xx省18', '1', '0');
INSERT INTO `t_areainfo` VALUES ('64', '0', 'xx省19', '1', '0');

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 queryChildrenAreaInfo;
DELIMITER ;;
CREATE FUNCTION queryChildrenAreaInfo(areaId INT)
RETURNS VARCHAR(4000)
BEGIN
DECLARE stemp VARCHAR(4000);
DECLARE stempChd VARCHAR(4000);
SET stemp='$';
SET stempChd = CAST(areaId AS CHAR);
WHILE stempChd IS NOT NULL DO
SET stemp= CONCAT(stemp,',',stempChd);
SELECT GROUP_CONCAT(id) INTO stempChd FROM t_areainfo WHERE FIND_IN_SET(parentId,stempChd)>0;
END WHILE;
RETURN stemp;
END
;;
DELIMITER ;

4、调用方式

SELECT queryChildrenAreaInfo(1);

查询id为4下面的所有节点

SELECT * FROM t_areainfo WHERE FIND_IN_SET(id,queryChildrenAreaInfo(4));

5、向上递归

DROP FUNCTION IF EXISTS queryChildrenAreaInfo1;
DELIMITER;;
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
;;
DELIMITER ;

6、调用方式

查询id为7的节点的所有上级节点：

SELECT * from t_areainfo where FIND_IN_SET(id,queryChildrenAreaInfo1(7));

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