MySQL中实现递归查询

对于数据库中的树形结构数据，如部门表，有时候，我们需要知道某部门的所有下属部分或者某部分的所有上级部门，这时候就需要用到mysql的递归查询

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));