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
按 Ctrl+C 复制代码
按 Ctrl+C 复制代码
2、初始数据
1INSERT INTO `t_areainfo` VALUES ('1', '0', '中国', '0', '0'); 2INSERT INTO `t_areainfo` VALUES ('2', '0', '华北区', '1', '0'); 3INSERT INTO `t_areainfo` VALUES ('3', '0', '华南区', '1', '0'); 4INSERT INTO `t_areainfo` VALUES ('4', '0', '北京', '2', '0'); 5INSERT INTO `t_areainfo` VALUES ('5', '0', '海淀区', '4', '0'); 6INSERT INTO `t_areainfo` VALUES ('6', '0', '丰台区', '4', '0'); 7INSERT INTO `t_areainfo` VALUES ('7', '0', '朝阳区', '4', '0'); 8INSERT INTO `t_areainfo` VALUES ('8', '0', '北京XX区1', '4', '0'); 9INSERT INTO `t_areainfo` VALUES ('9', '0', '北京XX区2', '4', '0'); 10INSERT INTO `t_areainfo` VALUES ('10', '0', '北京XX区3', '4', '0'); 11INSERT INTO `t_areainfo` VALUES ('11', '0', '北京XX区4', '4', '0'); 12INSERT INTO `t_areainfo` VALUES ('12', '0', '北京XX区5', '4', '0'); 13INSERT INTO `t_areainfo` VALUES ('13', '0', '北京XX区6', '4', '0'); 14INSERT INTO `t_areainfo` VALUES ('14', '0', '北京XX区7', '4', '0'); 15INSERT INTO `t_areainfo` VALUES ('15', '0', '北京XX区8', '4', '0'); 16INSERT INTO `t_areainfo` VALUES ('16', '0', '北京XX区9', '4', '0'); 17INSERT INTO `t_areainfo` VALUES ('17', '0', '北京XX区10', '4', '0'); 18INSERT INTO `t_areainfo` VALUES ('18', '0', '北京XX区11', '4', '0'); 19INSERT INTO `t_areainfo` VALUES ('19', '0', '北京XX区12', '4', '0'); 20INSERT INTO `t_areainfo` VALUES ('20', '0', '北京XX区13', '4', '0'); 21INSERT INTO `t_areainfo` VALUES ('21', '0', '北京XX区14', '4', '0'); 22INSERT INTO `t_areainfo` VALUES ('22', '0', '北京XX区15', '4', '0'); 23INSERT INTO `t_areainfo` VALUES ('23', '0', '北京XX区16', '4', '0'); 24INSERT INTO `t_areainfo` VALUES ('24', '0', '北京XX区17', '4', '0'); 25INSERT INTO `t_areainfo` VALUES ('25', '0', '北京XX区18', '4', '0'); 26INSERT INTO `t_areainfo` VALUES ('26', '0', '北京XX区19', '4', '0'); 27INSERT INTO `t_areainfo` VALUES ('27', '0', '北京XX区1', '4', '0'); 28INSERT INTO `t_areainfo` VALUES ('28', '0', '北京XX区2', '4', '0'); 29INSERT INTO `t_areainfo` VALUES ('29', '0', '北京XX区3', '4', '0'); 30INSERT INTO `t_areainfo` VALUES ('30', '0', '北京XX区4', '4', '0'); 31INSERT INTO `t_areainfo` VALUES ('31', '0', '北京XX区5', '4', '0'); 32INSERT INTO `t_areainfo` VALUES ('32', '0', '北京XX区6', '4', '0'); 33INSERT INTO `t_areainfo` VALUES ('33', '0', '北京XX区7', '4', '0'); 34INSERT INTO `t_areainfo` VALUES ('34', '0', '北京XX区8', '4', '0'); 35INSERT INTO `t_areainfo` VALUES ('35', '0', '北京XX区9', '4', '0'); 36INSERT INTO `t_areainfo` VALUES ('36', '0', '北京XX区10', '4', '0'); 37INSERT INTO `t_areainfo` VALUES ('37', '0', '北京XX区11', '4', '0'); 38INSERT INTO `t_areainfo` VALUES ('38', '0', '北京XX区12', '4', '0'); 39INSERT INTO `t_areainfo` VALUES ('39', '0', '北京XX区13', '4', '0'); 40INSERT INTO `t_areainfo` VALUES ('40', '0', '北京XX区14', '4', '0'); 41INSERT INTO `t_areainfo` VALUES ('41', '0', '北京XX区15', '4', '0'); 42INSERT INTO `t_areainfo` VALUES ('42', '0', '北京XX区16', '4', '0'); 43INSERT INTO `t_areainfo` VALUES ('43', '0', '北京XX区17', '4', '0'); 44INSERT INTO `t_areainfo` VALUES ('44', '0', '北京XX区18', '4', '0'); 45INSERT INTO `t_areainfo` VALUES ('45', '0', '北京XX区19', '4', '0'); 46INSERT INTO `t_areainfo` VALUES ('46', '0', 'xx省1', '1', '0'); 47INSERT INTO `t_areainfo` VALUES ('47', '0', 'xx省2', '1', '0'); 48INSERT INTO `t_areainfo` VALUES ('48', '0', 'xx省3', '1', '0'); 49INSERT INTO `t_areainfo` VALUES ('49', '0', 'xx省4', '1', '0'); 50INSERT INTO `t_areainfo` VALUES ('50', '0', 'xx省5', '1', '0'); 51INSERT INTO `t_areainfo` VALUES ('51', '0', 'xx省6', '1', '0'); 52INSERT INTO `t_areainfo` VALUES ('52', '0', 'xx省7', '1', '0'); 53INSERT INTO `t_areainfo` VALUES ('53', '0', 'xx省8', '1', '0'); 54INSERT INTO `t_areainfo` VALUES ('54', '0', 'xx省9', '1', '0'); 55INSERT INTO `t_areainfo` VALUES ('55', '0', 'xx省10', '1', '0'); 56INSERT INTO `t_areainfo` VALUES ('56', '0', 'xx省11', '1', '0'); 57INSERT INTO `t_areainfo` VALUES ('57', '0', 'xx省12', '1', '0'); 58INSERT INTO `t_areainfo` VALUES ('58', '0', 'xx省13', '1', '0'); 59INSERT INTO `t_areainfo` VALUES ('59', '0', 'xx省14', '1', '0'); 60INSERT INTO `t_areainfo` VALUES ('60', '0', 'xx省15', '1', '0'); 61INSERT INTO `t_areainfo` VALUES ('61', '0', 'xx省16', '1', '0'); 62INSERT INTO `t_areainfo` VALUES ('62', '0', 'xx省17', '1', '0'); 63INSERT INTO `t_areainfo` VALUES ('63', '0', 'xx省18', '1', '0'); 64INSERT 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：
1DROP FUNCTION IF EXISTS queryChildrenAreaInfo;DELIMITER ;; 2CREATE FUNCTION queryChildrenAreaInfo(areaId INT) 3RETURNS VARCHAR(4000) 4BEGIN 5DECLARE sTemp VARCHAR(4000); 6DECLARE sTempChd VARCHAR(4000); 7 8SET sTemp='$'; 9SET sTempChd = CAST(areaId AS CHAR); 10 11WHILE sTempChd IS NOT NULL DO 12SET sTemp= CONCAT(sTemp,',',sTempChd); 13SELECT GROUP_CONCAT(id) INTO sTempChd FROM t_areainfo WHERE FIND_IN_SET(parentId,sTempChd)>0; 14END WHILE; 15RETURN sTemp; 16END;;DELIMITER ;
4、调用方式
SELECT queryChildrenAreaInfo(1);
查询id为"4"下面的所有节点
SELECT * FROM t_areainfo WHERE FIND_IN_SET(id,queryChildrenAreaInfo(4));
5、向上递归
1DROP FUNCTION IF EXISTS queryChildrenAreaInfo1;DELIMITER;; 2CREATE FUNCTION queryChildrenAreaInfo1(areaId INT) 3RETURNS VARCHAR(4000) 4BEGIN 5DECLARE sTemp VARCHAR(4000); 6DECLARE sTempChd VARCHAR(4000); 7 8SET sTemp='$'; 9SET sTempChd = CAST(areaId AS CHAR); 10SET sTemp = CONCAT(sTemp,',',sTempChd); 11 12SELECT parentId INTO sTempChd FROM t_areainfo WHERE id = sTempChd; 13WHILE sTempChd <> 0 DO 14SET sTemp = CONCAT(sTemp,',',sTempChd); 15SELECT parentId INTO sTempChd FROM t_areainfo WHERE id = sTempChd; 16END WHILE; 17RETURN sTemp; 18END;;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));
