MySQL递归查询的3种实现方式实例

1.建表脚本

1.1.建表

drop table if exists `sys_region`;
create table `sys_region`  (
  `id` int(50) not null auto_increment comment '地区主键编号',
  `name` varchar(50) character set utf8 collate utf8_general_ci null default null comment '地区名称',
  `short_name` varchar(50) character set utf8 collate utf8_general_ci null default null comment '简称',
  `code` varchar(50) character set utf8 collate utf8_general_ci null default null comment '行政地区编号',
  `parent_code` varchar(50) character set utf8 collate utf8_general_ci null default null comment '父id',
  `level` int(2) null default null comment '1级：省、直辖市、自治区\r\n2级：地级市\r\n3级：市辖区、县（旗）、县级市、自治县（自治旗）、特区、林区\r\n4级：镇、乡、民族乡、县辖区、街道\r\n5级：村、居委会',
  `flag` int(1) null default null comment '0:正常 1废弃',
  primary key (`id`) using btree
) engine = innodb auto_increment = 182 character set = utf8 collate = utf8_general_ci comment = '地区表' row_format = dynamic;

1.2.插入数据

insert into `sys_region` values (1, '山东省', '鲁', '370000000000', null, 1, 0);
insert into `sys_region` values (2, '济南市', '济南', '370100000000', '370000000000', 2, 0);
insert into `sys_region` values (3, '市辖区', '市辖区', '370101000000', '370100000000', 3, 0);
insert into `sys_region` values (4, '历下区', '历下区', '370102000000', '370100000000', 3, 0);
insert into `sys_region` values (5, '市中区', '市中区', '370103000000', '370100000000', 3, 0);
insert into `sys_region` values (6, '槐荫区', '槐荫区', '370104000000', '370100000000', 3, 0);
insert into `sys_region` values (7, '天桥区', '天桥区', '370105000000', '370100000000', 3, 0);
insert into `sys_region` values (8, '历城区', '历城区', '370112000000', '370100000000', 3, 0);
insert into `sys_region` values (9, '长清区', '长清区', '370113000000', '370100000000', 3, 0);
insert into `sys_region` values (10, '章丘区', '章丘区', '370114000000', '370100000000', 3, 0);
insert into `sys_region` values (11, '济阳区', '济阳区', '370115000000', '370100000000', 3, 0);
insert into `sys_region` values (12, '莱芜区', '莱芜区', '370116000000', '370100000000', 3, 0);
insert into `sys_region` values (13, '钢城区', '钢城区', '370117000000', '370100000000', 3, 0);
insert into `sys_region` values (14, '平阴县', '平阴县', '370124000000', '370100000000', 3, 0);
insert into `sys_region` values (15, '商河县', '商河县', '370126000000', '370100000000', 3, 0);
insert into `sys_region` values (16, '济南高新技术产业开发区', '高新区', '370171000000', '370100000000', 3, 0);
insert into `sys_region` values (17, '解放路街道', '解放路街道', '370102001000', '370102000000', 4, 0);
insert into `sys_region` values (18, '千佛山街道', '千佛山街道', '370102002000', '370102000000', 4, 0);
insert into `sys_region` values (19, '趵突泉街道', '趵突泉街道', '370102003000', '370102000000', 4, 0);
insert into `sys_region` values (20, '泉城路街道', '泉城路街道', '370102004000', '370102000000', 4, 0);
insert into `sys_region` values (21, '大明湖街道', '大明湖街道', '370102005000', '370102000000', 4, 0);
insert into `sys_region` values (22, '东关街道', '东关街道', '370102006000', '370102000000', 4, 0);
insert into `sys_region` values (23, '文东街道', '文东街道', '370102007000', '370102000000', 4, 0);
insert into `sys_region` values (24, '建新街道', '建新街道', '370102008000', '370102000000', 4, 0);
insert into `sys_region` values (25, '甸柳街道', '甸柳街道', '370102009000', '370102000000', 4, 0);
insert into `sys_region` values (26, '燕山街道', '燕山街道', '370102010000', '370102000000', 4, 0);
insert into `sys_region` values (27, '姚家街道', '姚家街道', '370102011000', '370102000000', 4, 0);
insert into `sys_region` values (28, '龙洞街道', '龙洞街道', '370102012000', '370102000000', 4, 0);
insert into `sys_region` values (29, '智远街道', '智远街道', '370102013000', '370102000000', 4, 0);
insert into `sys_region` values (30, '大观园街道', '大观园街道', '370103002000', '370103000000', 4, 0);
insert into `sys_region` values (31, '杆石桥街道', '杆石桥街道', '370103003000', '370103000000', 4, 0);
insert into `sys_region` values (32, '四里村街道', '四里村街道', '370103004000', '370103000000', 4, 0);
insert into `sys_region` values (33, '魏家庄街道', '魏家庄街道', '370103006000', '370103000000', 4, 0);
insert into `sys_region` values (34, '二七街道', '二七街道', '370103008000', '370103000000', 4, 0);
insert into `sys_region` values (35, '七里山街道', '七里山街道', '370103009000', '370103000000', 4, 0);
insert into `sys_region` values (36, '六里山街道', '六里山街道', '370103010000', '370103000000', 4, 0);
insert into `sys_region` values (37, '舜玉路街道', '舜玉路街道', '370103012000', '370103000000', 4, 0);
insert into `sys_region` values (38, '泺源街道', '泺源街道', '370103014000', '370103000000', 4, 0);
insert into `sys_region` values (39, '王官庄街道', '王官庄街道', '370103015000', '370103000000', 4, 0);
insert into `sys_region` values (40, '舜耕街道', '舜耕街道', '370103016000', '370103000000', 4, 0);
insert into `sys_region` values (41, '白马山街道', '白马山街道', '370103017000', '370103000000', 4, 0);
insert into `sys_region` values (42, '七贤街道', '七贤街道', '370103018000', '370103000000', 4, 0);
insert into `sys_region` values (43, '十六里河街道', '十六里河街道', '370103019000', '370103000000', 4, 0);
insert into `sys_region` values (44, '兴隆街道', '兴隆街道', '370103020000', '370103000000', 4, 0);
insert into `sys_region` values (45, '党家街道', '党家街道', '370103021000', '370103000000', 4, 0);
insert into `sys_region` values (46, '陡沟街道', '陡沟街道', '370103022000', '370103000000', 4, 0);
insert into `sys_region` values (47, '振兴街街道', '振兴街街道', '370104001000', '370104000000', 4, 0);
insert into `sys_region` values (48, '中大槐树街道', '中大槐树街道', '370104002000', '370104000000', 4, 0);
insert into `sys_region` values (49, '道德街街道', '道德街街道', '370104003000', '370104000000', 4, 0);
insert into `sys_region` values (50, '西市场街道', '西市场街道', '370104004000', '370104000000', 4, 0);
insert into `sys_region` values (51, '五里沟街道', '五里沟街道', '370104005000', '370104000000', 4, 0);
insert into `sys_region` values (52, '营市街街道', '营市街街道', '370104006000', '370104000000', 4, 0);
insert into `sys_region` values (53, '青年公园街道', '青年公园街道', '370104007000', '370104000000', 4, 0);
insert into `sys_region` values (54, '南辛庄街道', '南辛庄街道', '370104008000', '370104000000', 4, 0);
insert into `sys_region` values (55, '段店北路街道', '段店北路街道', '370104009000', '370104000000', 4, 0);
insert into `sys_region` values (56, '张庄路街道', '张庄路街道', '370104010000', '370104000000', 4, 0);
insert into `sys_region` values (57, '匡山街道', '匡山街道', '370104011000', '370104000000', 4, 0);
insert into `sys_region` values (58, '美里湖街道', '美里湖街道', '370104012000', '370104000000', 4, 0);
insert into `sys_region` values (59, '腊山街道', '腊山街道', '370104013000', '370104000000', 4, 0);
insert into `sys_region` values (60, '兴福街道', '兴福街道', '370104014000', '370104000000', 4, 0);
insert into `sys_region` values (61, '玉清湖街道', '玉清湖街道', '370104015000', '370104000000', 4, 0);
insert into `sys_region` values (62, '吴家堡街道', '吴家堡街道', '370104016000', '370104000000', 4, 0);
insert into `sys_region` values (63, '无影山街道', '无影山街道', '370105001000', '370105000000', 4, 0);
insert into `sys_region` values (64, '天桥东街街道', '天桥东街街道', '370105003000', '370105000000', 4, 0);
insert into `sys_region` values (65, '北村街道', '北村街道', '370105004000', '370105000000', 4, 0);
insert into `sys_region` values (66, '南村街道', '南村街道', '370105005000', '370105000000', 4, 0);
insert into `sys_region` values (67, '堤口路街道', '堤口路街道', '370105006000', '370105000000', 4, 0);
insert into `sys_region` values (68, '北坦街道', '北坦街道', '370105007000', '370105000000', 4, 0);
insert into `sys_region` values (69, '制锦市街道', '制锦市街道', '370105009000', '370105000000', 4, 0);
insert into `sys_region` values (70, '宝华街道', '宝华街道', '370105010000', '370105000000', 4, 0);
insert into `sys_region` values (71, '官扎营街道', '官扎营街道', '370105011000', '370105000000', 4, 0);
insert into `sys_region` values (72, '纬北路街道', '纬北路街道', '370105012000', '370105000000', 4, 0);
insert into `sys_region` values (73, '药山街道', '药山街道', '370105013000', '370105000000', 4, 0);
insert into `sys_region` values (74, '北园街道', '北园街道', '370105014000', '370105000000', 4, 0);
insert into `sys_region` values (75, '泺口街道', '泺口街道', '370105015000', '370105000000', 4, 0);
insert into `sys_region` values (76, '桑梓店街道', '桑梓店街道', '370105016000', '370105000000', 4, 0);
insert into `sys_region` values (77, '大桥街道', '大桥街道', '370105017000', '370105000000', 4, 0);
insert into `sys_region` values (78, '山大路街道', '山大路街道', '370112001000', '370112000000', 4, 0);
insert into `sys_region` values (79, '洪家楼街道', '洪家楼街道', '370112002000', '370112000000', 4, 0);
insert into `sys_region` values (80, '东风街道', '东风街道', '370112003000', '370112000000', 4, 0);
insert into `sys_region` values (81, '全福街道', '全福街道', '370112004000', '370112000000', 4, 0);
insert into `sys_region` values (82, '华山街道', '华山街道', '370112007000', '370112000000', 4, 0);
insert into `sys_region` values (83, '荷花路街道', '荷花路街道', '370112008000', '370112000000', 4, 0);
insert into `sys_region` values (84, '王舍人街道', '王舍人街道', '370112009000', '370112000000', 4, 0);
insert into `sys_region` values (85, '鲍山街道', '鲍山街道', '370112010000', '370112000000', 4, 0);
insert into `sys_region` values (86, '郭店街道', '郭店街道', '370112011000', '370112000000', 4, 0);
insert into `sys_region` values (87, '唐冶街道', '唐冶街道', '370112012000', '370112000000', 4, 0);
insert into `sys_region` values (88, '港沟街道', '港沟街道', '370112013000', '370112000000', 4, 0);
insert into `sys_region` values (89, '董家街道', '董家街道', '370112016000', '370112000000', 4, 0);
insert into `sys_region` values (90, '彩石街道', '彩石街道', '370112017000', '370112000000', 4, 0);
insert into `sys_region` values (91, '仲宫街道', '仲宫街道', '370112018000', '370112000000', 4, 0);
insert into `sys_region` values (92, '柳埠街道', '柳埠街道', '370112019000', '370112000000', 4, 0);
insert into `sys_region` values (93, '唐王街道', '唐王街道', '370112020000', '370112000000', 4, 0);
insert into `sys_region` values (94, '西营街道', '西营街道', '370112021000', '370112000000', 4, 0);
insert into `sys_region` values (95, '文昌街道', '文昌街道', '370113001000', '370113000000', 4, 0);
insert into `sys_region` values (96, '崮云湖街道', '崮云湖街道', '370113002000', '370113000000', 4, 0);
insert into `sys_region` values (97, '平安街道', '平安街道', '370113003000', '370113000000', 4, 0);
insert into `sys_region` values (98, '五峰山街道', '五峰山街道', '370113004000', '370113000000', 4, 0);
insert into `sys_region` values (99, '归德街道', '归德街道', '370113005000', '370113000000', 4, 0);
insert into `sys_region` values (100, '张夏街道', '张夏街道', '370113006000', '370113000000', 4, 0);
insert into `sys_region` values (101, '万德街道', '万德街道', '370113007000', '370113000000', 4, 0);
insert into `sys_region` values (102, '孝里镇', '孝里镇', '370113102000', '370113000000', 4, 0);
insert into `sys_region` values (103, '马山镇', '马山镇', '370113107000', '370113000000', 4, 0);
insert into `sys_region` values (104, '双泉镇', '双泉镇', '370113108000', '370113000000', 4, 0);
insert into `sys_region` values (105, '明水街道', '明水街道', '370114001000', '370114000000', 4, 0);
insert into `sys_region` values (106, '双山街道', '双山街道', '370114002000', '370114000000', 4, 0);
insert into `sys_region` values (107, '枣园街道', '枣园街道', '370114003000', '370114000000', 4, 0);
insert into `sys_region` values (108, '龙山街道', '龙山街道', '370114004000', '370114000000', 4, 0);
insert into `sys_region` values (109, '埠村街道', '埠村街道', '370114005000', '370114000000', 4, 0);
insert into `sys_region` values (110, '圣井街道', '圣井街道', '370114006000', '370114000000', 4, 0);
insert into `sys_region` values (111, '普集街道', '普集街道', '370114007000', '370114000000', 4, 0);
insert into `sys_region` values (112, '绣惠街道', '绣惠街道', '370114008000', '370114000000', 4, 0);
insert into `sys_region` values (113, '相公庄街道', '相公庄街道', '370114009000', '370114000000', 4, 0);
insert into `sys_region` values (114, '文祖街道', '文祖街道', '370114010000', '370114000000', 4, 0);
insert into `sys_region` values (115, '官庄街道', '官庄街道', '370114011000', '370114000000', 4, 0);
insert into `sys_region` values (116, '高官寨街道', '高官寨街道', '370114012000', '370114000000', 4, 0);
insert into `sys_region` values (117, '白云湖街道', '白云湖街道', '370114013000', '370114000000', 4, 0);
insert into `sys_region` values (118, '宁家埠街道', '宁家埠街道', '370114014000', '370114000000', 4, 0);
insert into `sys_region` values (119, '曹范街道', '曹范街道', '370114015000', '370114000000', 4, 0);
insert into `sys_region` values (120, '刁镇', '刁镇', '370114100000', '370114000000', 4, 0);
insert into `sys_region` values (121, '垛庄镇', '垛庄镇', '370114101000', '370114000000', 4, 0);
insert into `sys_region` values (122, '黄河镇', '黄河镇', '370114102000', '370114000000', 4, 0);
insert into `sys_region` values (123, '济阳街道', '济阳街道', '370115001000', '370115000000', 4, 0);
insert into `sys_region` values (124, '济北街道', '济北街道', '370115002000', '370115000000', 4, 0);
insert into `sys_region` values (125, '崔寨街道', '崔寨街道', '370115003000', '370115000000', 4, 0);
insert into `sys_region` values (126, '孙耿街道', '孙耿街道', '370115004000', '370115000000', 4, 0);
insert into `sys_region` values (127, '回河街道', '回河街道', '370115005000', '370115000000', 4, 0);
insert into `sys_region` values (128, '太平街道', '太平街道', '370115006000', '370115000000', 4, 0);
insert into `sys_region` values (129, '垛石镇', '垛石镇', '370115101000', '370115000000', 4, 0);
insert into `sys_region` values (130, '曲堤镇', '曲堤镇', '370115103000', '370115000000', 4, 0);
insert into `sys_region` values (131, '仁风镇', '仁风镇', '370115104000', '370115000000', 4, 0);
insert into `sys_region` values (132, '新市镇', '新市镇', '370115110000', '370115000000', 4, 0);
insert into `sys_region` values (133, '凤城街道', '凤城街道', '370116001000', '370116000000', 4, 0);
insert into `sys_region` values (134, '张家洼街道', '张家洼街道', '370116002000', '370116000000', 4, 0);
insert into `sys_region` values (135, '高庄街道', '高庄街道', '370116003000', '370116000000', 4, 0);
insert into `sys_region` values (136, '鹏泉街道', '鹏泉街道', '370116004000', '370116000000', 4, 0);
insert into `sys_region` values (137, '口镇', '口镇', '370116100000', '370116000000', 4, 0);
insert into `sys_region` values (138, '羊里镇', '羊里镇', '370116101000', '370116000000', 4, 0);
insert into `sys_region` values (139, '方下镇', '方下镇', '370116102000', '370116000000', 4, 0);
insert into `sys_region` values (140, '牛泉镇', '牛泉镇', '370116103000', '370116000000', 4, 0);
insert into `sys_region` values (141, '苗山镇', '苗山镇', '370116104000', '370116000000', 4, 0);
insert into `sys_region` values (142, '雪野镇', '雪野镇', '370116105000', '370116000000', 4, 0);
insert into `sys_region` values (143, '大王庄镇', '大王庄镇', '370116106000', '370116000000', 4, 0);
insert into `sys_region` values (144, '寨里镇', '寨里镇', '370116107000', '370116000000', 4, 0);
insert into `sys_region` values (145, '杨庄镇', '杨庄镇', '370116108000', '370116000000', 4, 0);
insert into `sys_region` values (146, '茶业口镇', '茶业口镇', '370116109000', '370116000000', 4, 0);
insert into `sys_region` values (147, '和庄镇', '和庄镇', '370116110000', '370116000000', 4, 0);
insert into `sys_region` values (148, '艾山街道', '艾山街道', '370117001000', '370117000000', 4, 0);
insert into `sys_region` values (149, '里辛街道', '里辛街道', '370117002000', '370117000000', 4, 0);
insert into `sys_region` values (150, '汶源街道', '汶源街道', '370117003000', '370117000000', 4, 0);
insert into `sys_region` values (151, '颜庄镇', '颜庄镇', '370117100000', '370117000000', 4, 0);
insert into `sys_region` values (152, '辛庄镇', '辛庄镇', '370117103000', '370117000000', 4, 0);
insert into `sys_region` values (153, '棋山国家森林公园', '棋山国家森林公园', '370117400000', '370117000000', 4, 0);
insert into `sys_region` values (154, '高新技术开发区', '高新技术开发区', '370117401000', '370117000000', 4, 0);
insert into `sys_region` values (155, '榆山街道', '榆山街道', '370124001000', '370124000000', 4, 0);
insert into `sys_region` values (156, '锦水街道', '锦水街道', '370124002000', '370124000000', 4, 0);
insert into `sys_region` values (157, '东阿镇', '东阿镇', '370124102000', '370124000000', 4, 0);
insert into `sys_region` values (158, '孝直镇', '孝直镇', '370124103000', '370124000000', 4, 0);
insert into `sys_region` values (159, '孔村镇', '孔村镇', '370124104000', '370124000000', 4, 0);
insert into `sys_region` values (160, '洪范池镇', '洪范池镇', '370124105000', '370124000000', 4, 0);
insert into `sys_region` values (161, '玫瑰镇', '玫瑰镇', '370124106000', '370124000000', 4, 0);
insert into `sys_region` values (162, '安城镇', '安城镇', '370124107000', '370124000000', 4, 0);
insert into `sys_region` values (163, '许商街道', '许商街道', '370126001000', '370126000000', 4, 0);
insert into `sys_region` values (164, '殷巷镇', '殷巷镇', '370126101000', '370126000000', 4, 0);
insert into `sys_region` values (165, '怀仁镇', '怀仁镇', '370126102000', '370126000000', 4, 0);
insert into `sys_region` values (166, '龙桑寺镇', '龙桑寺镇', '370126104000', '370126000000', 4, 0);
insert into `sys_region` values (167, '郑路镇', '郑路镇', '370126105000', '370126000000', 4, 0);
insert into `sys_region` values (168, '贾庄镇', '贾庄镇', '370126106000', '370126000000', 4, 0);
insert into `sys_region` values (169, '玉皇庙镇', '玉皇庙镇', '370126107000', '370126000000', 4, 0);
insert into `sys_region` values (170, '白桥镇', '白桥镇', '370126108000', '370126000000', 4, 0);
insert into `sys_region` values (171, '孙集镇', '孙集镇', '370126109000', '370126000000', 4, 0);
insert into `sys_region` values (172, '韩庙镇', '韩庙镇', '370126110000', '370126000000', 4, 0);
insert into `sys_region` values (173, '沙河镇', '沙河镇', '370126111000', '370126000000', 4, 0);
insert into `sys_region` values (174, '张坊镇', '张坊镇', '370126112000', '370126000000', 4, 0);
insert into `sys_region` values (175, '舜华路街道', '舜华路街道', '370171001000', '370171000000', 4, 0);
insert into `sys_region` values (176, '孙村街道', '孙村街道', '370171002000', '370171000000', 4, 0);
insert into `sys_region` values (177, '巨野河街道', '巨野河街道', '370171003000', '370171000000', 4, 0);
insert into `sys_region` values (178, '遥墙街道', '遥墙街道', '370171004000', '370171000000', 4, 0);
insert into `sys_region` values (179, '临港街道', '临港街道', '370171005000', '370171000000', 4, 0);
insert into `sys_region` values (180, '创新谷街道办事处', '创新谷街道办事处', '370171400000', '370171000000', 4, 0);
insert into `sys_region` values (181, '章锦街道', '章锦街道', '370171401000', '370171000000', 4, 0);

2.递归查询三种实现方式

2.1. 方式一 创建自定义函数实现递归查询

注意：

1.创建函数的时候，可能会报错。this function has none of deterministic 在mysql安装根目录个人配置文件my.ini中添加一行：log_bin_trust_function_creators=1    然后重启mysql服务。

2.创建函数的时候用到了系统函数group_concat()，该函数默认长度是1024，在配置文件my.ini 中修改默认长度，添加一行语句：group_concat_max_len=102400    保存后重启mysql服务。查询sql select @@global.group_concat_max_len;

3.这种方式实现之后，调用简单，但是效率较慢，而且由于字段 、函数、 长度的的限制，数据量大的时候可能查询不全。适合小数据量下使用。

2.1.1. 查询子节点的函数 查询时  包含自身

创建函数： 

-- 查询子节点的函数  查询时包含自身
create definer=`root`@`localhost` function `querychildren_1_sys_region`(areaid varchar(15)) returns varchar(20000) charset utf8
begin
declare stemp varchar(20000);
declare stempchd varchar(20000);
set stemp='$';
set stempchd = areaid;
while stempchd is not null do
set stemp= concat(stemp,',',stempchd);
select group_concat(code) into stempchd from sys_region where find_in_set(parent_code,stempchd)>0;
end while;
return stemp;
end

查询示例：

-- 子节点 含自己
select * from sys_region where find_in_set(code,querychildren_1_sys_region('370000000000'));

 2.1.2. 查询子节点的函数 查询时  不包含自身

创建函数： 

-- 查询子节点的函数 查询时  不包含自身
create definer=`root`@`localhost` function `querychildren_sys_region`(areaid varchar(15)) returns varchar(21840) charset utf8
begin
declare stemp varchar(21840);
declare stempchd varchar(21840);
set stemp='$';
set stempchd = areaid;
while stempchd is not null do
if stempchd != areaid then 
set stemp= concat(stemp,',',stempchd);
end if;
select group_concat(code) into stempchd from sys_region where find_in_set(parent_code,stempchd)>0;
end while;
return stemp;
end

查询示例：

select * from  sys_region where find_in_set(code,querychildren_sys_region('370000000000'));

 2.1.3.查询父节点  查询的时候  包含自身

创建函数： 

-- 查询父节点  查询的时候 包含自身
create definer=`root`@`localhost` function `queryparent_1_sys_region`(areaid varchar(15)) returns varchar(21840) charset utf8
begin
declare stemp varchar(21840);
declare stempchd varchar(21840);
set stemp='$';
set stempchd = areaid;
-- set stemp = concat(stemp,',',stempchd);
-- select ifnull(parent_code,'') into stempchd from tgyi.sys_region  where code = stempchd;
while (stempchd <> '' ) do
set stemp = concat(stemp,',',stempchd);
select ifnull((select parent_code from tgyi.sys_region  where code = stempchd),'')  into stempchd ;
end while;
return stemp;
end

查询示例：

select * from sys_region where find_in_set(code,queryparent_1_sys_region('370171401000'));

 2.1.4.查询父节点  查询的时候  不包含自身

创建函数： 

-- 查询父节点   查询的时候  不包含自身
create definer=`root`@`localhost` function `queryparent_sys_region`(areaid varchar(15)) returns varchar(21840) charset utf8
begin
declare stemp varchar(21840);
declare stempchd varchar(21840);
set stemp='$';
set stempchd = areaid;
-- set stemp = concat(stemp,',',stempchd);
-- select ifnull(parent_code,'') into stempchd from tgyi.sys_region  where code = stempchd;
while (stempchd <> '' ) do
if stempchd != areaid then 
set stemp = concat(stemp,',',stempchd);
end if;
select ifnull((select parent_code from tgyi.sys_region  where code = stempchd),'')  into stempchd ;
end while;
return stemp;
end

查询示例：

select * from sys_region where find_in_set(code,queryparent_sys_region('370171401000'));

 2.2. 方式二  单纯使用sql  不创建函数  实现递归

注意：

写法比较复杂，但是适合mysql各版本，比较灵活。

2.2.1.查询子节点  含自己

查询sql脚本及效果截图：

 
-- 单纯使用sql递归 查询子节点  含自己
select t2.level_, t3.* 
from( 
select @codes as _ids, 
( select @codes := group_concat(code) 
from sys_region 
where find_in_set(parent_code, @codes) 
) as t1, 
@l := @l+1 as level_ 
from sys_region, 
(select @codes :='370000000000', @l := 0 ) t4
where @codes is not null 
) t2, sys_region t3 
where find_in_set(t3.code, t2._ids) 
order by level_, code
;

2.2.2.查询子节点  不含自己

查询sql脚本及效果截图：

-- 单纯使用sql递归 查询子节点  不含自己
select t2.level_, t3.* 
from( 
select @codes as _ids, 
( select @codes := group_concat(code) 
from sys_region 
where find_in_set(parent_code, @codes) 
) as t1, 
@l := @l+1 as level_ 
from sys_region, 
(select @codes :='370000000000', @l := -1 ) t4 
where @codes is not null 
) t2, sys_region t3 
where find_in_set(t3.code, t2._ids) 
and code !='370000000000'
order by level_, code
;

2.2.3.查询父节点  含自己

查询sql脚本及效果截图：

-- 单纯使用sql递归 查询父节点  含自己
select t2.level_, t3.* 
from( 
select @code as _code, 
( select @code := parent_code 
from sys_region 
where code = @code 
) as t1, 
@l := @l+1 as level_ 
from sys_region, 
(select @code := '370171401000', @l := 0 ) t4 
where @code is not null
) t2, sys_region t3
where t2._code = t3.code 
order by level_
;

2.2.4.查询父节点  不含自己

查询sql脚本及效果截图：

 -- 单纯使用sql递归 查询父节点  不含自己
select t2.level_, t3.* 
from( 
select @code as _code, 
( select @code := parent_code 
from sys_region 
where code = @code 
) as t1, 
@l := @l+1 as level_ 
from sys_region, 
(select @code := '370171401000', @l := -1 ) t4 
where @code is not null
) t2, sys_region t3
where t2._code = t3.code 
and t2._code != '370171401000' 
order by level_
;

 2.3. 方式三   mysql 8.0 版本以上 使用 with recursive 实现递归 注意：

写法比较简单，也比较灵活，但是只适用于mysql8.0及以上版本，这种写法其实和  postgresql 的写法是一样的。

2.3.1.查询子节点  含自己

查询sql脚本及效果截图：

 -- 查询子节点  含自己
with recursive recursion (id, name, short_name, code, parent_code, level, flag) as
(
select t1.id, t1.name, t1.short_name, t1.code, t1.parent_code, t1.level, t1.flag  
from sys_region t1
where t1.code='370000000000'
union all
select t2.id, t2.name, t2.short_name, t2.code, t2.parent_code, t2.level, t2.flag 
from sys_region t2, recursion t3
where t2.parent_code=t3.code
)
select t.id, t.name, t.short_name, t.code, t.parent_code, t.level, t.flag  
from recursion t
;

2.3.2.查询子节点  不含自己

查询sql脚本及效果截图：

 -- 查询子节点   不含自己
with recursive recursion (id, name, short_name, code, parent_code, level, flag) as
(
select t1.id, t1.name, t1.short_name, t1.code, t1.parent_code, t1.level, t1.flag  
from sys_region t1
where t1.code='370000000000'
union all
select t2.id, t2.name, t2.short_name, t2.code, t2.parent_code, t2.level, t2.flag 
from sys_region t2, recursion t3
where t2.parent_code=t3.code
)
select t.id, t.name, t.short_name, t.code, t.parent_code, t.level, t.flag  
from recursion t
where t.code!='370000000000'
;

2.3.3.查询父节点  含自己

查询sql脚本及效果截图：

 -- 查询父节点  含自己
with recursive recursion (id, name, short_name, code, parent_code, level, flag) as
(
select t1.id, t1.name, t1.short_name, t1.code, t1.parent_code, t1.level, t1.flag  
from sys_region t1
where t1.code='370171401000'
union all
select t2.id, t2.name, t2.short_name, t2.code, t2.parent_code, t2.level, t2.flag 
from sys_region t2, recursion t3
where t2.code=t3.parent_code
)
select t.id, t.name, t.short_name, t.code, t.parent_code, t.level, t.flag  
from recursion t
;

2.3.4.查询父节点  不含自己

查询sql脚本及效果截图：

 with recursive recursion (id, name, short_name, code, parent_code, level, flag) as
(
select t1.id, t1.name, t1.short_name, t1.code, t1.parent_code, t1.level, t1.flag  
from sys_region t1
where t1.code='370171401000'
union all
select t2.id, t2.name, t2.short_name, t2.code, t2.parent_code, t2.level, t2.flag 
from sys_region t2, recursion t3
where t2.code=t3.parent_code
)
select t.id, t.name, t.short_name, t.code, t.parent_code, t.level, t.flag  
from recursion t
where t.code!='370171401000'
;	

总结

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