关于区域表system_district：省市县街道四级地址表

需求：

1、将其设计成一张表

DROP TABLE IF EXISTS `system_district`;
CREATE TABLE `system_district` (
  `district_id`      bigint(20) unsigned NOT NULL AUTO_INCREMENT   COMMENT '区域ID',
  `parent_id`        bigint(20) unsigned NOT NULL                  COMMENT '父ID',
  `district_name`    varchar(200) NOT NULL                         COMMENT '区域名称',
  `short_name`       varchar(200) NOT NULL                         COMMENT '简称',
  `longitude`        decimal(10,7) NOT NULL DEFAULT '0.0000000'    COMMENT '经度',
  `latitude`         decimal(10,7) NOT NULL DEFAULT '0.0000000'    COMMENT '维度',
  `level`            int(11) NOT NULL DEFAULT '1'                  COMMENT '等级（地区级别 1-省、自治区、直辖市 2-地级市、地区、自治州、盟 3-市辖区、县级市、县 4-街道办-乡）',
  `sort`             int(11) NOT NULL DEFAULT '0'                  COMMENT '排序',
  `is_deleted`       tinyint(1) NOT NULL DEFAULT '0'               COMMENT '删除标志: 0未删除，1已删除',
  `create_time`      timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP  COMMENT '创建时间',
  `update_time`      timestamp NOT NULL DEFAULT '0000-00-00 00:00:00' COMMENT '修改时间',
  PRIMARY KEY (`district_id`)
) ENGINE=InnoDB AUTO_INCREMENT=659004503 DEFAULT CHARSET=utf8 COMMENT='区域表';

2、将其设计成三张表

省表：

DROP TABLE IF EXISTS `province`;
CREATE TABLE `province` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`code` varchar(6) NOT NULL,
`name` varchar(20) NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=35 DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of province
-- ----------------------------
INSERT INTO `province` VALUES ('1', '110000', '北京市');
INSERT INTO `province` VALUES ('2', '120000', '天津市');
INSERT INTO `province` VALUES ('3', '130000', '河北省');
INSERT INTO `province` VALUES ('4', '140000', '山西省');
INSERT INTO `province` VALUES ('5', '150000', '内蒙古');

市表：

DROP TABLE IF EXISTS `city`;
CREATE TABLE `city` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `code` varchar(6) NOT NULL,
  `name` varchar(20) NOT NULL,
  `provincecode` varchar(6) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=343 DEFAULT CHARSET=utf8;
 
-- ----------------------------
-- Records of city
-- ----------------------------
INSERT INTO `city` VALUES ('1', '110100', '北京市', '110000');
INSERT INTO `city` VALUES ('2', '130100', '石家庄市', '130000');
INSERT INTO `city` VALUES ('3', '130200', '唐山市', '130000');
INSERT INTO `city` VALUES ('4', '130300', '秦皇岛市', '130000');
INSERT INTO `city` VALUES ('5', '130400', '邯郸市', '130000');
INSERT INTO `city` VALUES ('6', '130500', '邢台市', '130000');
INSERT INTO `city` VALUES ('7', '130600', '保定市', '130000');
INSERT INTO `city` VALUES ('8', '130700', '张家口市', '130000');

县表：

DROP TABLE IF EXISTS `area`;
CREATE TABLE `area` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `code` varchar(6) NOT NULL,
  `name` varchar(20) NOT NULL,
  `citycode` varchar(6) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=MyISAM AUTO_INCREMENT=3145 DEFAULT CHARSET=utf8;
 
-- ----------------------------
-- Records of area
-- ----------------------------
INSERT INTO `area` VALUES ('1', '110101', '东城区', '110100');
INSERT INTO `area` VALUES ('2', '110102', '西城区', '110100');
INSERT INTO `area` VALUES ('3', '110103', '崇文区', '110100');
INSERT INTO `area` VALUES ('4', '110104', '宣武区', '110100');
INSERT INTO `area` VALUES ('5', '110105', '朝阳区', '110100');
INSERT INTO `area` VALUES ('6', '110106', '丰台区', '110100');
INSERT INTO `area` VALUES ('7', '110107', '石景山区', '110100');
INSERT INTO `area` VALUES ('8', '110108', '海淀区', '110100');
INSERT INTO `area` VALUES ('9', '110109', '门头沟区', '110100');
INSERT INTO `area` VALUES ('10', '110111', '房山区', '110100');
INSERT INTO `area` VALUES ('11', '110112', '通州区', '110100');
INSERT INTO `area` VALUES ('12', '110113', '顺义区', '110100');
INSERT INTO `area` VALUES ('13', '110114', '昌平区', '110100');