ehappy
css优先级 的 6大分类

第一优先级：无条件优先的属性只需要在属性后面使用**！important**。它会覆盖页面内任何位置定义的元素样式。ie6不支持该属性。

第二优先级：在html中给元素标签加style，即内联样式。该方法会造成css难以管理，所以不推荐使用。

第三优先级：由一个或多个id选择器来定义。例如，#id{margin:0;}会覆盖.classname{margin:3pxl}

第四优先级：由一个或多个类选择器、属性选择器、伪类选择器定义。如.classname{margin:3px}会覆盖div{margin:6px;}

第五优先级：由一个或多个类型选择器定义。如div{marigin:6px;}覆盖*{margin:10px；}

第六优先级：通配选择器，如*{marigin:6px;}

mysql递归查询

      本文转载，文章底部有我实践过程中遇到的问题总结博客，希望能够帮到大家。

2021SC@SDUSC

我是以山东济南的行政区划作为示例的，数据库是MySQL

话不多说，直接上示例代码!

目录

1.建表脚本

1.1.建表

1.2.插入数据

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：

2.1.1. 查询子节点的函数 查询时  包含自身

 2.1.2. 查询子节点的函数 查询时  不包含自身

 2.1.3.查询父节点  查询的时候  包含自身

 2.1.4.查询父节点  查询的时候  不包含自身

 2.2. 方式二  单纯使用sql  不创建函数  实现递归

注意：

2.2.1.查询子节点  含自己

2.2.2.查询子节点  不含自己

2.2.3.查询父节点  含自己

2.2.4.查询父节点  不含自己

 2.3. 方式三   MySQL 8.0 版本以上 使用 WITH RECURSIVE 实现递归

注意：

2.3.1.查询子节点  含自己

2.3.2.查询子节点  不含自己

2.3.3.查询父节点  含自己

2.3.4.查询父节点  不含自己

1.建表脚本

1.1.建表

  1. DROP TABLE IF EXISTS `sys_region`;
  2. CREATE TABLE `sys_region`  (
  3.   `id` int(50) NOT NULL AUTO_INCREMENT COMMENT '地区主键编号',
  4.   `name` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '地区名称',
  5.   `short_name` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '简称',
  6.   `code` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '行政地区编号',
  7.   `parent_code` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '父id',
  8.   `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',
  9.   `flag` int(1) NULL DEFAULT NULL COMMENT '0:正常 1废弃',
  10.   PRIMARY KEY (`id`) USING BTREE
  11. ) ENGINE = InnoDB AUTO_INCREMENT = 182 CHARACTER SET = utf8 COLLATE = utf8_general_ci COMMENT = '地区表' ROW_FORMAT = Dynamic;
  12.

1.2.插入数据

  1. INSERT INTO `sys_region` VALUES (1, '山东省', '鲁', '370000000000', NULL, 1, 0);
  2. INSERT INTO `sys_region` VALUES (2, '济南市', '济南', '370100000000', '370000000000', 2, 0);
  3. INSERT INTO `sys_region` VALUES (3, '市辖区', '市辖区', '370101000000', '370100000000', 3, 0);
  4. INSERT INTO `sys_region` VALUES (4, '历下区', '历下区', '370102000000', '370100000000', 3, 0);
  5. INSERT INTO `sys_region` VALUES (5, '市中区', '市中区', '370103000000', '370100000000', 3, 0);
  6. INSERT INTO `sys_region` VALUES (6, '槐荫区', '槐荫区', '370104000000', '370100000000', 3, 0);
  7. INSERT INTO `sys_region` VALUES (7, '天桥区', '天桥区', '370105000000', '370100000000', 3, 0);
  8. INSERT INTO `sys_region` VALUES (8, '历城区', '历城区', '370112000000', '370100000000', 3, 0);
  9. INSERT INTO `sys_region` VALUES (9, '长清区', '长清区', '370113000000', '370100000000', 3, 0);
  10. INSERT INTO `sys_region` VALUES (10, '章丘区', '章丘区', '370114000000', '370100000000', 3, 0);
  11. INSERT INTO `sys_region` VALUES (11, '济阳区', '济阳区', '370115000000', '370100000000', 3, 0);
  12. INSERT INTO `sys_region` VALUES (12, '莱芜区', '莱芜区', '370116000000', '370100000000', 3, 0);
  13. INSERT INTO `sys_region` VALUES (13, '钢城区', '钢城区', '370117000000', '370100000000', 3, 0);
  14. INSERT INTO `sys_region` VALUES (14, '平阴县', '平阴县', '370124000000', '370100000000', 3, 0);
  15. INSERT INTO `sys_region` VALUES (15, '商河县', '商河县', '370126000000', '370100000000', 3, 0);
  16. INSERT INTO `sys_region` VALUES (16, '济南高新技术产业开发区', '高新区', '370171000000', '370100000000', 3, 0);
  17. INSERT INTO `sys_region` VALUES (17, '解放路街道', '解放路街道', '370102001000', '370102000000', 4, 0);
  18. INSERT INTO `sys_region` VALUES (18, '千佛山街道', '千佛山街道', '370102002000', '370102000000', 4, 0);
  19. INSERT INTO `sys_region` VALUES (19, '趵突泉街道', '趵突泉街道', '370102003000', '370102000000', 4, 0);
  20. INSERT INTO `sys_region` VALUES (20, '泉城路街道', '泉城路街道', '370102004000', '370102000000', 4, 0);
  21. INSERT INTO `sys_region` VALUES (21, '大明湖街道', '大明湖街道', '370102005000', '370102000000', 4, 0);
  22. INSERT INTO `sys_region` VALUES (22, '东关街道', '东关街道', '370102006000', '370102000000', 4, 0);
  23. INSERT INTO `sys_region` VALUES (23, '文东街道', '文东街道', '370102007000', '370102000000', 4, 0);
  24. INSERT INTO `sys_region` VALUES (24, '建新街道', '建新街道', '370102008000', '370102000000', 4, 0);
  25. INSERT INTO `sys_region` VALUES (25, '甸柳街道', '甸柳街道', '370102009000', '370102000000', 4, 0);
  26. INSERT INTO `sys_region` VALUES (26, '燕山街道', '燕山街道', '370102010000', '370102000000', 4, 0);
  27. INSERT INTO `sys_region` VALUES (27, '姚家街道', '姚家街道', '370102011000', '370102000000', 4, 0);
  28. INSERT INTO `sys_region` VALUES (28, '龙洞街道', '龙洞街道', '370102012000', '370102000000', 4, 0);
  29. INSERT INTO `sys_region` VALUES (29, '智远街道', '智远街道', '370102013000', '370102000000', 4, 0);
  30. INSERT INTO `sys_region` VALUES (30, '大观园街道', '大观园街道', '370103002000', '370103000000', 4, 0);
  31. INSERT INTO `sys_region` VALUES (31, '杆石桥街道', '杆石桥街道', '370103003000', '370103000000', 4, 0);
  32. INSERT INTO `sys_region` VALUES (32, '四里村街道', '四里村街道', '370103004000', '370103000000', 4, 0);
  33. INSERT INTO `sys_region` VALUES (33, '魏家庄街道', '魏家庄街道', '370103006000', '370103000000', 4, 0);
  34. INSERT INTO `sys_region` VALUES (34, '二七街道', '二七街道', '370103008000', '370103000000', 4, 0);
  35. INSERT INTO `sys_region` VALUES (35, '七里山街道', '七里山街道', '370103009000', '370103000000', 4, 0);
  36. INSERT INTO `sys_region` VALUES (36, '六里山街道', '六里山街道', '370103010000', '370103000000', 4, 0);
  37. INSERT INTO `sys_region` VALUES (37, '舜玉路街道', '舜玉路街道', '370103012000', '370103000000', 4, 0);
  38. INSERT INTO `sys_region` VALUES (38, '泺源街道', '泺源街道', '370103014000', '370103000000', 4, 0);
  39. INSERT INTO `sys_region` VALUES (39, '王官庄街道', '王官庄街道', '370103015000', '370103000000', 4, 0);
  40. INSERT INTO `sys_region` VALUES (40, '舜耕街道', '舜耕街道', '370103016000', '370103000000', 4, 0);
  41. INSERT INTO `sys_region` VALUES (41, '白马山街道', '白马山街道', '370103017000', '370103000000', 4, 0);
  42. INSERT INTO `sys_region` VALUES (42, '七贤街道', '七贤街道', '370103018000', '370103000000', 4, 0);
  43. INSERT INTO `sys_region` VALUES (43, '十六里河街道', '十六里河街道', '370103019000', '370103000000', 4, 0);
  44. INSERT INTO `sys_region` VALUES (44, '兴隆街道', '兴隆街道', '370103020000', '370103000000', 4, 0);
  45. INSERT INTO `sys_region` VALUES (45, '党家街道', '党家街道', '370103021000', '370103000000', 4, 0);
  46. INSERT INTO `sys_region` VALUES (46, '陡沟街道', '陡沟街道', '370103022000', '370103000000', 4, 0);
  47. INSERT INTO `sys_region` VALUES (47, '振兴街街道', '振兴街街道', '370104001000', '370104000000', 4, 0);
  48. INSERT INTO `sys_region` VALUES (48, '中大槐树街道', '中大槐树街道', '370104002000', '370104000000', 4, 0);
  49. INSERT INTO `sys_region` VALUES (49, '道德街街道', '道德街街道', '370104003000', '370104000000', 4, 0);
  50. INSERT INTO `sys_region` VALUES (50, '西市场街道', '西市场街道', '370104004000', '370104000000', 4, 0);
  51. INSERT INTO `sys_region` VALUES (51, '五里沟街道', '五里沟街道', '370104005000', '370104000000', 4, 0);
  52. INSERT INTO `sys_region` VALUES (52, '营市街街道', '营市街街道', '370104006000', '370104000000', 4, 0);
  53. INSERT INTO `sys_region` VALUES (53, '青年公园街道', '青年公园街道', '370104007000', '370104000000', 4, 0);
  54. INSERT INTO `sys_region` VALUES (54, '南辛庄街道', '南辛庄街道', '370104008000', '370104000000', 4, 0);
  55. INSERT INTO `sys_region` VALUES (55, '段店北路街道', '段店北路街道', '370104009000', '370104000000', 4, 0);
  56. INSERT INTO `sys_region` VALUES (56, '张庄路街道', '张庄路街道', '370104010000', '370104000000', 4, 0);
  57. INSERT INTO `sys_region` VALUES (57, '匡山街道', '匡山街道', '370104011000', '370104000000', 4, 0);
  58. INSERT INTO `sys_region` VALUES (58, '美里湖街道', '美里湖街道', '370104012000', '370104000000', 4, 0);
  59. INSERT INTO `sys_region` VALUES (59, '腊山街道', '腊山街道', '370104013000', '370104000000', 4, 0);
  60. INSERT INTO `sys_region` VALUES (60, '兴福街道', '兴福街道', '370104014000', '370104000000', 4, 0);
  61. INSERT INTO `sys_region` VALUES (61, '玉清湖街道', '玉清湖街道', '370104015000', '370104000000', 4, 0);
  62. INSERT INTO `sys_region` VALUES (62, '吴家堡街道', '吴家堡街道', '370104016000', '370104000000', 4, 0);
  63. INSERT INTO `sys_region` VALUES (63, '无影山街道', '无影山街道', '370105001000', '370105000000', 4, 0);
  64. INSERT INTO `sys_region` VALUES (64, '天桥东街街道', '天桥东街街道', '370105003000', '370105000000', 4, 0);
  65. INSERT INTO `sys_region` VALUES (65, '北村街道', '北村街道', '370105004000', '370105000000', 4, 0);
  66. INSERT INTO `sys_region` VALUES (66, '南村街道', '南村街道', '370105005000', '370105000000', 4, 0);
  67. INSERT INTO `sys_region` VALUES (67, '堤口路街道', '堤口路街道', '370105006000', '370105000000', 4, 0);
  68. INSERT INTO `sys_region` VALUES (68, '北坦街道', '北坦街道', '370105007000', '370105000000', 4, 0);
  69. INSERT INTO `sys_region` VALUES (69, '制锦市街道', '制锦市街道', '370105009000', '370105000000', 4, 0);
  70. INSERT INTO `sys_region` VALUES (70, '宝华街道', '宝华街道', '370105010000', '370105000000', 4, 0);
  71. INSERT INTO `sys_region` VALUES (71, '官扎营街道', '官扎营街道', '370105011000', '370105000000', 4, 0);
  72. INSERT INTO `sys_region` VALUES (72, '纬北路街道', '纬北路街道', '370105012000', '370105000000', 4, 0);
  73. INSERT INTO `sys_region` VALUES (73, '药山街道', '药山街道', '370105013000', '370105000000', 4, 0);
  74. INSERT INTO `sys_region` VALUES (74, '北园街道', '北园街道', '370105014000', '370105000000', 4, 0);
  75. INSERT INTO `sys_region` VALUES (75, '泺口街道', '泺口街道', '370105015000', '370105000000', 4, 0);
  76. INSERT INTO `sys_region` VALUES (76, '桑梓店街道', '桑梓店街道', '370105016000', '370105000000', 4, 0);
  77. INSERT INTO `sys_region` VALUES (77, '大桥街道', '大桥街道', '370105017000', '370105000000', 4, 0);
  78. INSERT INTO `sys_region` VALUES (78, '山大路街道', '山大路街道', '370112001000', '370112000000', 4, 0);
  79. INSERT INTO `sys_region` VALUES (79, '洪家楼街道', '洪家楼街道', '370112002000', '370112000000', 4, 0);
  80. INSERT INTO `sys_region` VALUES (80, '东风街道', '东风街道', '370112003000', '370112000000', 4, 0);
  81. INSERT INTO `sys_region` VALUES (81, '全福街道', '全福街道', '370112004000', '370112000000', 4, 0);
  82. INSERT INTO `sys_region` VALUES (82, '华山街道', '华山街道', '370112007000', '370112000000', 4, 0);
  83. INSERT INTO `sys_region` VALUES (83, '荷花路街道', '荷花路街道', '370112008000', '370112000000', 4, 0);
  84. INSERT INTO `sys_region` VALUES (84, '王舍人街道', '王舍人街道', '370112009000', '370112000000', 4, 0);
  85. INSERT INTO `sys_region` VALUES (85, '鲍山街道', '鲍山街道', '370112010000', '370112000000', 4, 0);
  86. INSERT INTO `sys_region` VALUES (86, '郭店街道', '郭店街道', '370112011000', '370112000000', 4, 0);
  87. INSERT INTO `sys_region` VALUES (87, '唐冶街道', '唐冶街道', '370112012000', '370112000000', 4, 0);
  88. INSERT INTO `sys_region` VALUES (88, '港沟街道', '港沟街道', '370112013000', '370112000000', 4, 0);
  89. INSERT INTO `sys_region` VALUES (89, '董家街道', '董家街道', '370112016000', '370112000000', 4, 0);
  90. INSERT INTO `sys_region` VALUES (90, '彩石街道', '彩石街道', '370112017000', '370112000000', 4, 0);
  91. INSERT INTO `sys_region` VALUES (91, '仲宫街道', '仲宫街道', '370112018000', '370112000000', 4, 0);
  92. INSERT INTO `sys_region` VALUES (92, '柳埠街道', '柳埠街道', '370112019000', '370112000000', 4, 0);
  93. INSERT INTO `sys_region` VALUES (93, '唐王街道', '唐王街道', '370112020000', '370112000000', 4, 0);
  94. INSERT INTO `sys_region` VALUES (94, '西营街道', '西营街道', '370112021000', '370112000000', 4, 0);
  95. INSERT INTO `sys_region` VALUES (95, '文昌街道', '文昌街道', '370113001000', '370113000000', 4, 0);
  96. INSERT INTO `sys_region` VALUES (96, '崮云湖街道', '崮云湖街道', '370113002000', '370113000000', 4, 0);
  97. INSERT INTO `sys_region` VALUES (97, '平安街道', '平安街道', '370113003000', '370113000000', 4, 0);
  98. INSERT INTO `sys_region` VALUES (98, '五峰山街道', '五峰山街道', '370113004000', '370113000000', 4, 0);
  99. INSERT INTO `sys_region` VALUES (99, '归德街道', '归德街道', '370113005000', '370113000000', 4, 0);
  100. INSERT INTO `sys_region` VALUES (100, '张夏街道', '张夏街道', '370113006000', '370113000000', 4, 0);
  101. INSERT INTO `sys_region` VALUES (101, '万德街道', '万德街道', '370113007000', '370113000000', 4, 0);
  102. INSERT INTO `sys_region` VALUES (102, '孝里镇', '孝里镇', '370113102000', '370113000000', 4, 0);
  103. INSERT INTO `sys_region` VALUES (103, '马山镇', '马山镇', '370113107000', '370113000000', 4, 0);
  104. INSERT INTO `sys_region` VALUES (104, '双泉镇', '双泉镇', '370113108000', '370113000000', 4, 0);
  105. INSERT INTO `sys_region` VALUES (105, '明水街道', '明水街道', '370114001000', '370114000000', 4, 0);
  106. INSERT INTO `sys_region` VALUES (106, '双山街道', '双山街道', '370114002000', '370114000000', 4, 0);
  107. INSERT INTO `sys_region` VALUES (107, '枣园街道', '枣园街道', '370114003000', '370114000000', 4, 0);
  108. INSERT INTO `sys_region` VALUES (108, '龙山街道', '龙山街道', '370114004000', '370114000000', 4, 0);
  109. INSERT INTO `sys_region` VALUES (109, '埠村街道', '埠村街道', '370114005000', '370114000000', 4, 0);
  110. INSERT INTO `sys_region` VALUES (110, '圣井街道', '圣井街道', '370114006000', '370114000000', 4, 0);
  111. INSERT INTO `sys_region` VALUES (111, '普集街道', '普集街道', '370114007000', '370114000000', 4, 0);
  112. INSERT INTO `sys_region` VALUES (112, '绣惠街道', '绣惠街道', '370114008000', '370114000000', 4, 0);
  113. INSERT INTO `sys_region` VALUES (113, '相公庄街道', '相公庄街道', '370114009000', '370114000000', 4, 0);
  114. INSERT INTO `sys_region` VALUES (114, '文祖街道', '文祖街道', '370114010000', '370114000000', 4, 0);
  115. INSERT INTO `sys_region` VALUES (115, '官庄街道', '官庄街道', '370114011000', '370114000000', 4, 0);
  116. INSERT INTO `sys_region` VALUES (116, '高官寨街道', '高官寨街道', '370114012000', '370114000000', 4, 0);
  117. INSERT INTO `sys_region` VALUES (117, '白云湖街道', '白云湖街道', '370114013000', '370114000000', 4, 0);
  118. INSERT INTO `sys_region` VALUES (118, '宁家埠街道', '宁家埠街道', '370114014000', '370114000000', 4, 0);
  119. INSERT INTO `sys_region` VALUES (119, '曹范街道', '曹范街道', '370114015000', '370114000000', 4, 0);
  120. INSERT INTO `sys_region` VALUES (120, '刁镇', '刁镇', '370114100000', '370114000000', 4, 0);
  121. INSERT INTO `sys_region` VALUES (121, '垛庄镇', '垛庄镇', '370114101000', '370114000000', 4, 0);
  122. INSERT INTO `sys_region` VALUES (122, '黄河镇', '黄河镇', '370114102000', '370114000000', 4, 0);
  123. INSERT INTO `sys_region` VALUES (123, '济阳街道', '济阳街道', '370115001000', '370115000000', 4, 0);
  124. INSERT INTO `sys_region` VALUES (124, '济北街道', '济北街道', '370115002000', '370115000000', 4, 0);
  125. INSERT INTO `sys_region` VALUES (125, '崔寨街道', '崔寨街道', '370115003000', '370115000000', 4, 0);
  126. INSERT INTO `sys_region` VALUES (126, '孙耿街道', '孙耿街道', '370115004000', '370115000000', 4, 0);
  127. INSERT INTO `sys_region` VALUES (127, '回河街道', '回河街道', '370115005000', '370115000000', 4, 0);
  128. INSERT INTO `sys_region` VALUES (128, '太平街道', '太平街道', '370115006000', '370115000000', 4, 0);
  129. INSERT INTO `sys_region` VALUES (129, '垛石镇', '垛石镇', '370115101000', '370115000000', 4, 0);
  130. INSERT INTO `sys_region` VALUES (130, '曲堤镇', '曲堤镇', '370115103000', '370115000000', 4, 0);
  131. INSERT INTO `sys_region` VALUES (131, '仁风镇', '仁风镇', '370115104000', '370115000000', 4, 0);
  132. INSERT INTO `sys_region` VALUES (132, '新市镇', '新市镇', '370115110000', '370115000000', 4, 0);
  133. INSERT INTO `sys_region` VALUES (133, '凤城街道', '凤城街道', '370116001000', '370116000000', 4, 0);
  134. INSERT INTO `sys_region` VALUES (134, '张家洼街道', '张家洼街道', '370116002000', '370116000000', 4, 0);
  135. INSERT INTO `sys_region` VALUES (135, '高庄街道', '高庄街道', '370116003000', '370116000000', 4, 0);
  136. INSERT INTO `sys_region` VALUES (136, '鹏泉街道', '鹏泉街道', '370116004000', '370116000000', 4, 0);
  137. INSERT INTO `sys_region` VALUES (137, '口镇', '口镇', '370116100000', '370116000000', 4, 0);
  138. INSERT INTO `sys_region` VALUES (138, '羊里镇', '羊里镇', '370116101000', '370116000000', 4, 0);
  139. INSERT INTO `sys_region` VALUES (139, '方下镇', '方下镇', '370116102000', '370116000000', 4, 0);
  140. INSERT INTO `sys_region` VALUES (140, '牛泉镇', '牛泉镇', '370116103000', '370116000000', 4, 0);
  141. INSERT INTO `sys_region` VALUES (141, '苗山镇', '苗山镇', '370116104000', '370116000000', 4, 0);
  142. INSERT INTO `sys_region` VALUES (142, '雪野镇', '雪野镇', '370116105000', '370116000000', 4, 0);
  143. INSERT INTO `sys_region` VALUES (143, '大王庄镇', '大王庄镇', '370116106000', '370116000000', 4, 0);
  144. INSERT INTO `sys_region` VALUES (144, '寨里镇', '寨里镇', '370116107000', '370116000000', 4, 0);
  145. INSERT INTO `sys_region` VALUES (145, '杨庄镇', '杨庄镇', '370116108000', '370116000000', 4, 0);
  146. INSERT INTO `sys_region` VALUES (146, '茶业口镇', '茶业口镇', '370116109000', '370116000000', 4, 0);
  147. INSERT INTO `sys_region` VALUES (147, '和庄镇', '和庄镇', '370116110000', '370116000000', 4, 0);
  148. INSERT INTO `sys_region` VALUES (148, '艾山街道', '艾山街道', '370117001000', '370117000000', 4, 0);
  149. INSERT INTO `sys_region` VALUES (149, '里辛街道', '里辛街道', '370117002000', '370117000000', 4, 0);
  150. INSERT INTO `sys_region` VALUES (150, '汶源街道', '汶源街道', '370117003000', '370117000000', 4, 0);
  151. INSERT INTO `sys_region` VALUES (151, '颜庄镇', '颜庄镇', '370117100000', '370117000000', 4, 0);
  152. INSERT INTO `sys_region` VALUES (152, '辛庄镇', '辛庄镇', '370117103000', '370117000000', 4, 0);
  153. 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);
  154. INSERT INTO `sys_region` VALUES (154, '高新技术开发区', '高新技术开发区', '370117401000', '370117000000', 4, 0);
  155. INSERT INTO `sys_region` VALUES (155, '榆山街道', '榆山街道', '370124001000', '370124000000', 4, 0);
  156. INSERT INTO `sys_region` VALUES (156, '锦水街道', '锦水街道', '370124002000', '370124000000', 4, 0);
  157. INSERT INTO `sys_region` VALUES (157, '东阿镇', '东阿镇', '370124102000', '370124000000', 4, 0);
  158. INSERT INTO `sys_region` VALUES (158, '孝直镇', '孝直镇', '370124103000', '370124000000', 4, 0);
  159. INSERT INTO `sys_region` VALUES (159, '孔村镇', '孔村镇', '370124104000', '370124000000', 4, 0);
  160. INSERT INTO `sys_region` VALUES (160, '洪范池镇', '洪范池镇', '370124105000', '370124000000', 4, 0);
  161. INSERT INTO `sys_region` VALUES (161, '玫瑰镇', '玫瑰镇', '370124106000', '370124000000', 4, 0);
  162. INSERT INTO `sys_region` VALUES (162, '安城镇', '安城镇', '370124107000', '370124000000', 4, 0);
  163. INSERT INTO `sys_region` VALUES (163, '许商街道', '许商街道', '370126001000', '370126000000', 4, 0);
  164. INSERT INTO `sys_region` VALUES (164, '殷巷镇', '殷巷镇', '370126101000', '370126000000', 4, 0);
  165. INSERT INTO `sys_region` VALUES (165, '怀仁镇', '怀仁镇', '370126102000', '370126000000', 4, 0);
  166. INSERT INTO `sys_region` VALUES (166, '龙桑寺镇', '龙桑寺镇', '370126104000', '370126000000', 4, 0);
  167. INSERT INTO `sys_region` VALUES (167, '郑路镇', '郑路镇', '370126105000', '370126000000', 4, 0);
  168. INSERT INTO `sys_region` VALUES (168, '贾庄镇', '贾庄镇', '370126106000', '370126000000', 4, 0);
  169. INSERT INTO `sys_region` VALUES (169, '玉皇庙镇', '玉皇庙镇', '370126107000', '370126000000', 4, 0);
  170. INSERT INTO `sys_region` VALUES (170, '白桥镇', '白桥镇', '370126108000', '370126000000', 4, 0);
  171. INSERT INTO `sys_region` VALUES (171, '孙集镇', '孙集镇', '370126109000', '370126000000', 4, 0);
  172. INSERT INTO `sys_region` VALUES (172, '韩庙镇', '韩庙镇', '370126110000', '370126000000', 4, 0);
  173. INSERT INTO `sys_region` VALUES (173, '沙河镇', '沙河镇', '370126111000', '370126000000', 4, 0);
  174. INSERT INTO `sys_region` VALUES (174, '张坊镇', '张坊镇', '370126112000', '370126000000', 4, 0);
  175. INSERT INTO `sys_region` VALUES (175, '舜华路街道', '舜华路街道', '370171001000', '370171000000', 4, 0);
  176. INSERT INTO `sys_region` VALUES (176, '孙村街道', '孙村街道', '370171002000', '370171000000', 4, 0);
  177. INSERT INTO `sys_region` VALUES (177, '巨野河街道', '巨野河街道', '370171003000', '370171000000', 4, 0);
  178. INSERT INTO `sys_region` VALUES (178, '遥墙街道', '遥墙街道', '370171004000', '370171000000', 4, 0);
  179. INSERT INTO `sys_region` VALUES (179, '临港街道', '临港街道', '370171005000', '370171000000', 4, 0);
  180. 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);
  181. INSERT INTO `sys_region` VALUES (181, '章锦街道', '章锦街道', '370171401000', '370171000000', 4, 0);
  182.

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： 

  1. -- 查询子节点的函数  查询时包含自身
  2. CREATE DEFINER=`root`@`localhost` FUNCTION `queryChildren_1_sys_region`(areaId VARCHAR(15)) RETURNS varchar(20000) CHARSET utf8
  3. BEGIN
  4. DECLARE sTemp VARCHAR(20000);
  5. DECLARE sTempChd VARCHAR(20000);
  6.  
  7. SET sTemp=’$’;
  8. SET sTempChd = areaId;
  9.  
  10. WHILE sTempChd IS NOT NULL DO
  11.  
  12. SET sTemp= CONCAT(sTemp,’,’,sTempChd);
  13. SELECT GROUP_CONCAT(code) INTO sTempChd FROM sys_region WHERE FIND_IN_SET(parent_code,sTempChd)>0;
  14.  
  15. END WHILE;
  16. RETURN sTemp;
  17. END
  18.

查询示例：

  1. -- 子节点 含自己
  2. 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： 

  1. -- 查询子节点的函数 查询时  不包含自身
  2. CREATE DEFINER=`root`@`localhost` FUNCTION `queryChildren_sys_region`(areaId VARCHAR(15)) RETURNS varchar(21840) CHARSET utf8
  3. BEGIN
  4. DECLARE sTemp VARCHAR(21840);
  5. DECLARE sTempChd VARCHAR(21840);
  6.  
  7. SET sTemp=’$’;
  8. SET sTempChd = areaId;
  9.  
  10. WHILE sTempChd IS NOT NULL DO
  11.  
  12. if sTempChd != areaId then
  13. SET sTemp= CONCAT(sTemp,’,’,sTempChd);
  14. end if;
  15.  
  16. SELECT GROUP_CONCAT(code) INTO sTempChd FROM sys_region WHERE FIND_IN_SET(parent_code,sTempChd)>0;
  17.  
  18. END WHILE;
  19. RETURN sTemp;
  20. END
  21.

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： 

  1. -- 查询父节点  查询的时候 包含自身
  2. CREATE DEFINER=root@localhost FUNCTION queryParent_1_sys_region(areaId VARCHAR(15)) RETURNS varchar(21840) CHARSET utf8
  3. BEGIN
  4. DECLARE sTemp VARCHAR(21840);
  5. DECLARE sTempChd VARCHAR(21840);
  6.  
  7. SET sTemp=’$’;
  8. SET sTempChd = areaId;
  9.  
  10. – SET sTemp = CONCAT(sTemp,’,’,sTempChd);
  11. – SELECT IFNULL(parent_code,’’) INTO sTempChd FROM tgyi.sys_region WHERE code = sTempChd;
  12.  
  13. WHILE (sTempChd <> ‘’ ) DO
  14.  
  15. SET sTemp = CONCAT(sTemp,’,’,sTempChd);
  16. select ifnull((SELECT parent_code FROM tgyi.sys_region WHERE code = sTempChd),’’) INTO sTempChd ;
  17.  
  18. END WHILE;
  19.  
  20. RETURN sTemp;
  21. END
  22.

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： 

  1. -- 查询父节点   查询的时候  不包含自身
  2. CREATE DEFINER=`root`@`localhost` FUNCTION `queryParent_sys_region`(areaId VARCHAR(15)) RETURNS varchar(21840) CHARSET utf8
  3. BEGIN
  4. DECLARE sTemp VARCHAR(21840);
  5. DECLARE sTempChd VARCHAR(21840);
  6.  
  7. SET sTemp=’$’;
  8. SET sTempChd = areaId;
  9.  
  10. – SET sTemp = CONCAT(sTemp,’,’,sTempChd);
  11. – SELECT IFNULL(parent_code,’’) INTO sTempChd FROM tgyi.sys_region WHERE code = sTempChd;
  12.  
  13. WHILE (sTempChd <> ‘’ ) DO
  14.  
  15. if sTempChd != areaId then
  16. SET sTemp = CONCAT(sTemp,’,’,sTempChd);
  17. end if;
  18.  
  19. select ifnull((SELECT parent_code FROM tgyi.sys_region WHERE code = sTempChd),’’) INTO sTempChd ;
  20.  
  21. END WHILE;
  22.  
  23. RETURN sTemp;
  24. END
  25.

查询示例：

  1. SELECT * from  sys_region where FIND_IN_SET(code,queryParent_sys_region('370171401000'));
  2.

 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：

  1. -- 单纯使用SQL递归 查询子节点  含自己
  2. SELECT T2.level_, T3.* 
  3.   FROM( 
  4. 	SELECT @codes as _ids, 
  5. 			( SELECT @codes := GROUP_CONCAT(code) 
  6. 				FROM sys_region 
  7. 			   WHERE FIND_IN_SET(parent_code, @codes) 
  8. 			) as T1, 
  9. 		   @l := @l+1 as level_ 
  10. 	  FROM sys_region, 
  11. 		  (SELECT @codes :='370000000000', @l := 0 ) T4
  12. 	 WHERE @codes IS NOT NULL 
  13. 	   ) T2, sys_region T3 
  14.   WHERE FIND_IN_SET(T3.code, T2._ids) 
  15.   ORDER BY level_, code;
  16.

2.2.2.查询子节点  不含自己

查询SQL脚本及效果截图：

  1. -- 单纯使用SQL递归 查询子节点  不含自己
  2. SELECT T2.level_, T3.* 
  3.   FROM( 
  4. 	SELECT @codes as _ids, 
  5. 			( SELECT @codes := GROUP_CONCAT(code) 
  6. 				FROM sys_region 
  7. 			   WHERE FIND_IN_SET(parent_code, @codes) 
  8. 			) as T1, 
  9. 		   @l := @l+1 as level_ 
  10. 	  FROM sys_region, 
  11. 		  (SELECT @codes :='370000000000', @l := -1 ) T4 
  12. 	 WHERE @codes IS NOT NULL 
  13. 	   ) T2, sys_region T3 
  14.   WHERE FIND_IN_SET(T3.code, T2._ids) 
  15. 	  and code !='370000000000'
  16.   ORDER BY level_, code;
  17.

2.2.3.查询父节点  含自己

查询SQL脚本及效果截图：

  1. -- 单纯使用SQL递归 查询父节点  含自己
  2. SELECT T2.level_, T3.* 
  3.   FROM( 
  4. 	SELECT @code as _code, 
  5. 			( SELECT @code := parent_code 
  6. 				FROM sys_region 
  7. 			   WHERE code = @code 
  8. 			) as T1, 
  9. 		   @l := @l+1 as level_ 
  10. 	  FROM sys_region, 
  11. 		  (SELECT @code := '370171401000', @l := 0 ) T4 
  12. 	 WHERE @code is not null
  13. 	) T2, sys_region T3
  14.  WHERE T2._code = T3.code 
  15.  ORDER BY level_;
  16.

2.2.4.查询父节点  不含自己

查询SQL脚本及效果截图：

  1.  -- 单纯使用SQL递归 查询父节点  不含自己
  2. SELECT T2.level_, T3.* 
  3.   FROM( 
  4. 	SELECT @code as _code, 
  5. 			( SELECT @code := parent_code 
  6. 				FROM sys_region 
  7. 			   WHERE code = @code 
  8. 			) as T1, 
  9. 		   @l := @l+1 as level_ 
  10. 	  FROM sys_region, 
  11. 		  (SELECT @code := '370171401000', @l := -1 ) T4 
  12. 	 WHERE @code is not null
  13. 	) T2, sys_region T3
  14.  WHERE T2._code = T3.code 
  15.    and T2._code != '370171401000' 
  16.  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：

  1. -- 查询子节点  含自己
  2.  WITH RECURSIVE recursion (id, name, short_name, code, parent_code, level, flag) AS
  3. (
  4.   SELECT T1.id, T1.name, T1.short_name, T1.code, T1.parent_code, T1.level, T1.flag  
  5. 	  from sys_region T1
  6. 	 where T1.code='370000000000'
  7.   UNION ALL
  8. SELECT T2.id, T2.name, T2.short_name, T2.code, T2.parent_code, T2.level, T2.flag
  9. from sys_region T2, recursion T3
  10. WHERE T2.parent_code=T3.code
  11. )
  12. SELECT T.id, T.name, T.short_name, T.code, T.parent_code, T.level, T.flag
  13. FROM recursion T;
  14.

2.3.2.查询子节点  不含自己

查询SQL脚本及效果截图：

  1.  -- 查询子节点   不含自己
  2.  WITH RECURSIVE recursion (id, name, short_name, code, parent_code, level, flag) AS
  3. (
  4.   SELECT T1.id, T1.name, T1.short_name, T1.code, T1.parent_code, T1.level, T1.flag  
  5. 	  from sys_region T1
  6. 	 where T1.code='370000000000'
  7.   UNION ALL
  8. SELECT T2.id, T2.name, T2.short_name, T2.code, T2.parent_code, T2.level, T2.flag
  9. from sys_region T2, recursion T3
  10. WHERE T2.parent_code=T3.code
  11. )
  12. SELECT T.id, T.name, T.short_name, T.code, T.parent_code, T.level, T.flag
  13. FROM recursion T
  14. where T.code!=‘370000000000’;
  15.

2.3.3.查询父节点  含自己

查询SQL脚本及效果截图：

  1.  -- 查询父节点  含自己
  2.  WITH RECURSIVE recursion (id, name, short_name, code, parent_code, level, flag) AS
  3. (
  4.   SELECT T1.id, T1.name, T1.short_name, T1.code, T1.parent_code, T1.level, T1.flag  
  5. 	  from sys_region T1
  6. 	 where T1.code='370171401000'
  7.   UNION ALL
  8. SELECT T2.id, T2.name, T2.short_name, T2.code, T2.parent_code, T2.level, T2.flag
  9. from sys_region T2, recursion T3
  10. WHERE T2.code=T3.parent_code
  11. )
  12. SELECT T.id, T.name, T.short_name, T.code, T.parent_code, T.level, T.flag
  13. FROM recursion T;
  14.

2.3.4.查询父节点  不含自己

查询SQL脚本及效果截图：

  1.  WITH RECURSIVE recursion (id, name, short_name, code, parent_code, level, flag) AS
  2. (
  3.   SELECT T1.id, T1.name, T1.short_name, T1.code, T1.parent_code, T1.level, T1.flag  
  4. 	  from sys_region T1
  5. 	 where T1.code='370171401000'
  6.   UNION ALL
  7. SELECT T2.id, T2.name, T2.short_name, T2.code, T2.parent_code, T2.level, T2.flag
  8. from sys_region T2, recursion T3
  9. WHERE T2.code=T3.parent_code
  10. )
  11. SELECT T.id, T.name, T.short_name, T.code, T.parent_code, T.level, T.flag
  12. FROM recursion T
  13. where T.code!=‘370171401000’;
  14.

在我自己实践过程中，使用 "方式二  单纯使用sql  不创建函数  实现递归" ，遇到过一些坑，因此我写了一篇博客，希望能够帮到大家。

原文：  Mysql递归调用，报错：Subquery returns more than 1 row         

本文转载，原文地址：    Mysql递归查询   ，感谢作者。

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