ajax下拉框省市级联动

效果

• 初始访问页面
  

• 选中省会，自动刷新页面
  
  

sql数据

--  省市联动数据

CREATE TABLE PROVINCE (
       PID NUMBER PRIMARY KEY,
       PNAME VARCHAR(20) NOT NULL
)

SELECT * FROM PROVINCE

INSERT INTO province VALUES (1, '北京市');
INSERT INTO province VALUES (2, '天津市');
INSERT INTO province VALUES (3, '上海市');
INSERT INTO province VALUES (4, '重庆市');
INSERT INTO province VALUES (5, '河北省');
INSERT INTO province VALUES (6, '山西省');
INSERT INTO province VALUES (7, '台湾省');
INSERT INTO province VALUES (8, '辽宁省');
INSERT INTO province VALUES (9, '吉林省');
INSERT INTO province VALUES (10, '黑龙江省');
INSERT INTO province VALUES (11, '江苏省');
INSERT INTO province VALUES (12, '浙江省');
INSERT INTO province VALUES (13, '安徽省');
INSERT INTO province VALUES (14, '福建省');
INSERT INTO province VALUES (15, '江西省');
INSERT INTO province VALUES (16, '山东省');
INSERT INTO province VALUES (17, '河南省');
INSERT INTO province VALUES (18, '湖北省');
INSERT INTO province VALUES (19, '湖南省');
INSERT INTO province VALUES (20, '广东省');
INSERT INTO province VALUES (21, '甘肃省');
INSERT INTO province VALUES (22, '四川省');
INSERT INTO province VALUES (23, '贵州省');
INSERT INTO province VALUES (24, '海南省');
INSERT INTO province VALUES (25, '云南省');
INSERT INTO province VALUES (26, '青海省');
INSERT INTO province VALUES (27, '陕西省');
INSERT INTO province VALUES (28, '广西壮族自治区');
INSERT INTO province VALUES (29, '西藏自治区');
INSERT INTO province VALUES (30, '宁夏回族自治区');
INSERT INTO province VALUES (31, '新疆维吾尔自治区');
INSERT INTO province VALUES (32, '内蒙古自治区');
INSERT INTO province VALUES (33, '澳门特别行政区');
INSERT INTO province VALUES (34, '香港特别行政区');


CREATE TABLE city (
Cid NUMBER NOT NULL primary key,
pId NUMBER NOT NULL,
Cname varchar(100) NOT NULL 
)

-- DROP TABLE CITY

SELECT * FROM CITY ORDER BY CID ASC

SELECT * FROM CITY WHERE PID = 1

-- 区
INSERT INTO city VALUES (1, 1, '北京市');
INSERT INTO city VALUES (2, 2, '天津市');
INSERT INTO city VALUES (3, 3, '上海市');
INSERT INTO city VALUES (4, 4, '重庆市');
INSERT INTO city VALUES (5, 5, '石家庄市');
INSERT INTO city VALUES (6, 5, '唐山市');
INSERT INTO city VALUES (7, 5, '秦皇岛市');
INSERT INTO city VALUES (8, 5, '邯郸市');
INSERT INTO city VALUES (9, 5, '邢台市');
INSERT INTO city VALUES (10, 5, '保定市');
INSERT INTO city VALUES (11, 5, '张家口市');
INSERT INTO city VALUES (12, 5, '承德市');
INSERT INTO city VALUES (13, 5, '沧州市');
INSERT INTO city VALUES (14, 5, '廊坊市');
INSERT INTO city VALUES (15, 5, '衡水市');
INSERT INTO city VALUES (16, 6, '太原市');
INSERT INTO city VALUES (17, 6, '大同市');
INSERT INTO city VALUES (18, 6, '阳泉市');
INSERT INTO city VALUES (19, 6, '长治市');
INSERT INTO city VALUES (20, 6, '晋城市');
INSERT INTO city VALUES (21, 6, '朔州市');
INSERT INTO city VALUES (22, 6, '晋中市');
INSERT INTO city VALUES (23, 6, '运城市');
INSERT INTO city VALUES (24, 6, '忻州市');
INSERT INTO city VALUES (25, 6, '吕梁市');
INSERT INTO city VALUES (27, 7, '宜兰县');
INSERT INTO city VALUES (36, 7, '南投县');
INSERT INTO city VALUES (42, 7, '云林县');
INSERT INTO city VALUES (43, 7, '嘉义县');
INSERT INTO city VALUES (44, 7, '台南县');
INSERT INTO city VALUES (45, 7, '高雄县');
INSERT INTO city VALUES (46, 7, '屏东县');
INSERT INTO city VALUES (47, 7, '澎湖县');
INSERT INTO city VALUES (48, 7, '台东县');
INSERT INTO city VALUES (49, 7, '花莲县');
INSERT INTO city VALUES (50, 8, '沈阳市');
INSERT INTO city VALUES (51, 8, '大连市');
INSERT INTO city VALUES (52, 8, '鞍山市');
INSERT INTO city VALUES (53, 8, '抚顺市');
INSERT INTO city VALUES (54, 8, '本溪市');
INSERT INTO city VALUES (55, 8, '丹东市');
INSERT INTO city VALUES (56, 8, '锦州市');
INSERT INTO city VALUES (57, 8, '营口市');
INSERT INTO city VALUES (58, 8, '阜新市');
INSERT INTO city VALUES (59, 8, '辽阳市');
INSERT INTO city VALUES (60, 8, '盘锦市');
INSERT INTO city VALUES (61, 8, '铁岭市');
INSERT INTO city VALUES (62, 8, '朝阳市');
INSERT INTO city VALUES (63, 8, '葫芦岛市');
INSERT INTO city VALUES (64, 9, '长春市');
INSERT INTO city VALUES (65, 9, '吉林市');
INSERT INTO city VALUES (66, 9, '四平市');
INSERT INTO city VALUES (67, 9, '辽源市');
INSERT INTO city VALUES (68, 9, '通化市');
INSERT INTO city VALUES (69, 9, '白山市');
INSERT INTO city VALUES (70, 9, '松原市');
INSERT INTO city VALUES (71, 9, '白城市');
INSERT INTO city VALUES (72, 9, '延边朝鲜族自治州');
INSERT INTO city VALUES (73, 10, '哈尔滨市');
INSERT INTO city VALUES (74, 10, '齐齐哈尔市');
INSERT INTO city VALUES (75, 10, '鹤岗市');
INSERT INTO city VALUES (76, 10, '双鸭山市');
INSERT INTO city VALUES (77, 10, '鸡西市');
INSERT INTO city VALUES (78, 10, '大庆市');
INSERT INTO city VALUES (79, 10, '伊春市');
INSERT INTO city VALUES (80, 10, '牡丹江市');
INSERT INTO city VALUES (81, 10, '佳木斯市');
INSERT INTO city VALUES (82, 10, '七台河市');
INSERT INTO city VALUES (83, 10, '黑河市');
INSERT INTO city VALUES (84, 10, '绥化市');
INSERT INTO city VALUES (85, 10, '大兴安岭地区');
INSERT INTO city VALUES (86, 11, '南京市');
INSERT INTO city VALUES (87, 11, '无锡市');
INSERT INTO city VALUES (88, 11, '徐州市');
INSERT INTO city VALUES (89, 11, '常州市');
INSERT INTO city VALUES (90, 11, '苏州市');
INSERT INTO city VALUES (91, 11, '南通市');
INSERT INTO city VALUES (92, 11, '连云港市');
INSERT INTO city VALUES (93, 11, '淮安市');
INSERT INTO city VALUES (94, 11, '盐城市');
INSERT INTO city VALUES (95, 11, '扬州市');
INSERT INTO city VALUES (96, 11, '镇江市');
INSERT INTO city VALUES (97, 11, '泰州市');
INSERT INTO city VALUES (98, 11, '宿迁市');
INSERT INTO city VALUES (99, 12, '杭州市');
INSERT INTO city VALUES (100, 12, '宁波市');
INSERT INTO city VALUES (101, 12, '温州市');
INSERT INTO city VALUES (102, 12, '嘉兴市');
INSERT INTO city VALUES (103, 12, '湖州市');
INSERT INTO city VALUES (104, 12, '绍兴市');
INSERT INTO city VALUES (105, 12, '金华市');
INSERT INTO city VALUES (106, 12, '衢州市');
INSERT INTO city VALUES (107, 12, '舟山市');
INSERT INTO city VALUES (108, 12, '台州市');
INSERT INTO city VALUES (109, 12, '丽水市');
INSERT INTO city VALUES (110, 13, '合肥市');
INSERT INTO city VALUES (111, 13, '芜湖市');
INSERT INTO city VALUES (112, 13, '蚌埠市');
INSERT INTO city VALUES (113, 13, '淮南市');
INSERT INTO city VALUES (114, 13, '马鞍山市');
INSERT INTO city VALUES (115, 13, '淮北市');
INSERT INTO city VALUES (116, 13, '铜陵市');
INSERT INTO city VALUES (117, 13, '安庆市');
INSERT INTO city VALUES (118, 13, '黄山市');
INSERT INTO city VALUES (119, 13, '滁州市');
INSERT INTO city VALUES (120, 13, '阜阳市');
INSERT INTO city VALUES (121, 13, '宿州市');
INSERT INTO city VALUES (122, 13, '巢湖市');
INSERT INTO city VALUES (123, 13, '六安市');
INSERT INTO city VALUES (124, 13, '亳州市');
INSERT INTO city VALUES (125, 13, '池州市');
INSERT INTO city VALUES (126, 13, '宣城市');
INSERT INTO city VALUES (127, 14, '福州市');
INSERT INTO city VALUES (128, 14, '厦门市');
INSERT INTO city VALUES (129, 14, '莆田市');
INSERT INTO city VALUES (130, 14, '三明市');
INSERT INTO city VALUES (131, 14, '泉州市');
INSERT INTO city VALUES (132, 14, '漳州市');
INSERT INTO city VALUES (133, 14, '南平市');
INSERT INTO city VALUES (134, 14, '龙岩市');
INSERT INTO city VALUES (135, 14, '宁德市');
INSERT INTO city VALUES (136, 15, '南昌市');
INSERT INTO city VALUES (137, 15, '景德镇市');
INSERT INTO city VALUES (138, 15, '萍乡市');
INSERT INTO city VALUES (139, 15, '九江市');
INSERT INTO city VALUES (140, 15, '新余市');
INSERT INTO city VALUES (141, 15, '鹰潭市');
INSERT INTO city VALUES (142, 15, '赣州市');
INSERT INTO city VALUES (143, 15, '吉安市');
INSERT INTO city VALUES (144, 15, '宜春市');
INSERT INTO city VALUES (145, 15, '抚州市');
INSERT INTO city VALUES (146, 15, '上饶市');
INSERT INTO city VALUES (147, 16, '济南市');
INSERT INTO city VALUES (148, 16, '青岛市');
INSERT INTO city VALUES (149, 16, '淄博市');
INSERT INTO city VALUES (150, 16, '枣庄市');
INSERT INTO city VALUES (151, 16, '东营市');
INSERT INTO city VALUES (152, 16, '烟台市');
INSERT INTO city VALUES (153, 16, '潍坊市');
INSERT INTO city VALUES (154, 16, '济宁市');
INSERT INTO city VALUES (155, 16, '泰安市');
INSERT INTO city VALUES (156, 16, '威海市');
INSERT INTO city VALUES (157, 16, '日照市');
INSERT INTO city VALUES (158, 16, '莱芜市');
INSERT INTO city VALUES (159, 16, '临沂市');
INSERT INTO city VALUES (160, 16, '德州市');
INSERT INTO city VALUES (161, 16, '聊城市');
INSERT INTO city VALUES (162, 16, '滨州市');
INSERT INTO city VALUES (163, 16, '菏泽市');
INSERT INTO city VALUES (164, 17, '郑州市');
INSERT INTO city VALUES (165, 17, '开封市');
INSERT INTO city VALUES (166, 17, '洛阳市');
INSERT INTO city VALUES (167, 17, '平顶山市');
INSERT INTO city VALUES (168, 17, '安阳市');
INSERT INTO city VALUES (169, 17, '鹤壁市');
INSERT INTO city VALUES (170, 17, '新乡市');
INSERT INTO city VALUES (171, 17, '焦作市');
INSERT INTO city VALUES (172, 17, '濮阳市');
INSERT INTO city VALUES (173, 17, '许昌市');
INSERT INTO city VALUES (174, 17, '漯河市');
INSERT INTO city VALUES (175, 17, '三门峡市');
INSERT INTO city VALUES (176, 17, '南阳市');
INSERT INTO city VALUES (177, 17, '商丘市');
INSERT INTO city VALUES (178, 17, '信阳市');
INSERT INTO city VALUES (179, 17, '周口市');
INSERT INTO city VALUES (180, 17, '驻马店市');
INSERT INTO city VALUES (181, 17, '济源市');
INSERT INTO city VALUES (182, 18, '武汉市');
INSERT INTO city VALUES (183, 18, '黄石市');
INSERT INTO city VALUES (184, 18, '十堰市');
INSERT INTO city VALUES (185, 18, '荆州市');
INSERT INTO city VALUES (186, 18, '宜昌市');
INSERT INTO city VALUES (187, 18, '襄樊市');
INSERT INTO city VALUES (188, 18, '鄂州市');
INSERT INTO city VALUES (189, 18, '荆门市');
INSERT INTO city VALUES (190, 18, '孝感市');
INSERT INTO city VALUES (191, 18, '黄冈市');
INSERT INTO city VALUES (192, 18, '咸宁市');
INSERT INTO city VALUES (193, 18, '随州市');
INSERT INTO city VALUES (194, 18, '仙桃市');
INSERT INTO city VALUES (195, 18, '天门市');
INSERT INTO city VALUES (196, 18, '潜江市');
INSERT INTO city VALUES (197, 18, '神农架林区');
INSERT INTO city VALUES (198, 18, '恩施土家族苗族自治州');
INSERT INTO city VALUES (199, 19, '长沙市');
INSERT INTO city VALUES (200, 19, '株洲市');
INSERT INTO city VALUES (201, 19, '湘潭市');
INSERT INTO city VALUES (202, 19, '衡阳市');
INSERT INTO city VALUES (203, 19, '邵阳市');
INSERT INTO city VALUES (204, 19, '岳阳市');
INSERT INTO city VALUES (205, 19, '常德市');
INSERT INTO city VALUES (206, 19, '张家界市');
INSERT INTO city VALUES (207, 19, '益阳市');
INSERT INTO city VALUES (208, 19, '郴州市');
INSERT INTO city VALUES (209, 19, '永州市');
INSERT INTO city VALUES (210, 19, '怀化市');
INSERT INTO city VALUES (211, 19, '娄底市');
INSERT INTO city VALUES (212, 19, '湘西土家族苗族自治州');
INSERT INTO city VALUES (213, 20, '广州市');
INSERT INTO city VALUES (214, 20, '深圳市');
INSERT INTO city VALUES (215, 20, '珠海市');
INSERT INTO city VALUES (216, 20, '汕头市');
INSERT INTO city VALUES (217, 20, '韶关市');
INSERT INTO city VALUES (218, 20, '佛山市');
INSERT INTO city VALUES (219, 20, '江门市');
INSERT INTO city VALUES (220, 20, '湛江市');
INSERT INTO city VALUES (221, 20, '茂名市');
INSERT INTO city VALUES (222, 20, '肇庆市');
INSERT INTO city VALUES (223, 20, '惠州市');
INSERT INTO city VALUES (224, 20, '梅州市');
INSERT INTO city VALUES (225, 20, '汕尾市');
INSERT INTO city VALUES (226, 20, '河源市');
INSERT INTO city VALUES (227, 20, '阳江市');
INSERT INTO city VALUES (228, 20, '清远市');
INSERT INTO city VALUES (229, 20, '东莞市');
INSERT INTO city VALUES (230, 20, '中山市');
INSERT INTO city VALUES (231, 20, '潮州市');
INSERT INTO city VALUES (232, 20, '揭阳市');
INSERT INTO city VALUES (233, 20, '云浮市');
INSERT INTO city VALUES (234, 21, '兰州市');
INSERT INTO city VALUES (235, 21, '金昌市');
INSERT INTO city VALUES (236, 21, '白银市');
INSERT INTO city VALUES (237, 21, '天水市');
INSERT INTO city VALUES (238, 21, '嘉峪关市');
INSERT INTO city VALUES (239, 21, '武威市');
INSERT INTO city VALUES (240, 21, '张掖市');
INSERT INTO city VALUES (241, 21, '平凉市');
INSERT INTO city VALUES (242, 21, '酒泉市');
INSERT INTO city VALUES (243, 21, '庆阳市');
INSERT INTO city VALUES (244, 21, '定西市');
INSERT INTO city VALUES (245, 21, '陇南市');
INSERT INTO city VALUES (246, 21, '临夏回族自治州');
INSERT INTO city VALUES (247, 21, '甘南藏族自治州');
INSERT INTO city VALUES (248, 22, '成都市');
INSERT INTO city VALUES (249, 22, '自贡市');
INSERT INTO city VALUES (250, 22, '攀枝花市');
INSERT INTO city VALUES (251, 22, '泸州市');
INSERT INTO city VALUES (252, 22, '德阳市');
INSERT INTO city VALUES (253, 22, '绵阳市');
INSERT INTO city VALUES (254, 22, '广元市');
INSERT INTO city VALUES (255, 22, '遂宁市');
INSERT INTO city VALUES (256, 22, '内江市');
INSERT INTO city VALUES (257, 22, '乐山市');
INSERT INTO city VALUES (258, 22, '南充市');
INSERT INTO city VALUES (259, 22, '眉山市');
INSERT INTO city VALUES (260, 22, '宜宾市');
INSERT INTO city VALUES (261, 22, '广安市');
INSERT INTO city VALUES (262, 22, '达州市');
INSERT INTO city VALUES (263, 22, '雅安市');
INSERT INTO city VALUES (264, 22, '巴中市');
INSERT INTO city VALUES (265, 22, '资阳市');
INSERT INTO city VALUES (266, 22, '阿坝藏族羌族自治州');
INSERT INTO city VALUES (267, 22, '甘孜藏族自治州');
INSERT INTO city VALUES (268, 22, '凉山彝族自治州');
INSERT INTO city VALUES (269, 23, '贵阳市');
INSERT INTO city VALUES (270, 23, '六盘水市');
INSERT INTO city VALUES (271, 23, '遵义市');
INSERT INTO city VALUES (272, 23, '安顺市');
INSERT INTO city VALUES (273, 23, '铜仁地区');
INSERT INTO city VALUES (274, 23, '毕节地区');
INSERT INTO city VALUES (275, 23, '黔西南布依族苗族自治州');
INSERT INTO city VALUES (276, 23, '黔东南苗族侗族自治州');
INSERT INTO city VALUES (277, 23, '黔南布依族苗族自治州');
INSERT INTO city VALUES (278, 24, '海口市');
INSERT INTO city VALUES (279, 24, '三亚市');
INSERT INTO city VALUES (280, 24, '五指山市');
INSERT INTO city VALUES (281, 24, '琼海市');
INSERT INTO city VALUES (282, 24, '儋州市');
INSERT INTO city VALUES (283, 24, '文昌市');
INSERT INTO city VALUES (284, 24, '万宁市');
INSERT INTO city VALUES (285, 24, '东方市');
INSERT INTO city VALUES (286, 24, '澄迈县');
INSERT INTO city VALUES (287, 24, '定安县');
INSERT INTO city VALUES (288, 24, '屯昌县');
INSERT INTO city VALUES (289, 24, '临高县');
INSERT INTO city VALUES (290, 24, '白沙黎族自治县');
INSERT INTO city VALUES (291, 24, '昌江黎族自治县');
INSERT INTO city VALUES (292, 24, '乐东黎族自治县');
INSERT INTO city VALUES (293, 24, '陵水黎族自治县');
INSERT INTO city VALUES (294, 24, '保亭黎族苗族自治县');
INSERT INTO city VALUES (295, 24, '琼中黎族苗族自治县');
INSERT INTO city VALUES (296, 25, '昆明市');
INSERT INTO city VALUES (297, 25, '曲靖市');
INSERT INTO city VALUES (298, 25, '玉溪市');
INSERT INTO city VALUES (299, 25, '保山市');
INSERT INTO city VALUES (300, 25, '昭通市');
INSERT INTO city VALUES (301, 25, '丽江市');
INSERT INTO city VALUES (302, 25, '思茅市');
INSERT INTO city VALUES (303, 25, '临沧市');
INSERT INTO city VALUES (304, 25, '文山壮族苗族自治州');
INSERT INTO city VALUES (305, 25, '红河哈尼族彝族自治州');
INSERT INTO city VALUES (306, 25, '西双版纳傣族自治州');
INSERT INTO city VALUES (307, 25, '楚雄彝族自治州');
INSERT INTO city VALUES (308, 25, '大理白族自治州');
INSERT INTO city VALUES (309, 25, '德宏傣族景颇族自治州');
INSERT INTO city VALUES (310, 25, '怒江傈傈族自治州');
INSERT INTO city VALUES (311, 25, '迪庆藏族自治州');
INSERT INTO city VALUES (312, 26, '西宁市');
INSERT INTO city VALUES (313, 26, '海东地区');
INSERT INTO city VALUES (314, 26, '海北藏族自治州');
INSERT INTO city VALUES (315, 26, '黄南藏族自治州');
INSERT INTO city VALUES (316, 26, '海南藏族自治州');
INSERT INTO city VALUES (317, 26, '果洛藏族自治州');
INSERT INTO city VALUES (318, 26, '玉树藏族自治州');
INSERT INTO city VALUES (319, 26, '海西蒙古族藏族自治州');
INSERT INTO city VALUES (320, 27, '西安市');
INSERT INTO city VALUES (321, 27, '铜川市');
INSERT INTO city VALUES (322, 27, '宝鸡市');
INSERT INTO city VALUES (323, 27, '咸阳市');
INSERT INTO city VALUES (324, 27, '渭南市');
INSERT INTO city VALUES (325, 27, '延安市');
INSERT INTO city VALUES (326, 27, '汉中市');
INSERT INTO city VALUES (327, 27, '榆林市');
INSERT INTO city VALUES (328, 27, '安康市');
INSERT INTO city VALUES (329, 27, '商洛市');
INSERT INTO city VALUES (330, 28, '南宁市');
INSERT INTO city VALUES (331, 28, '柳州市');
INSERT INTO city VALUES (332, 28, '桂林市');
INSERT INTO city VALUES (333, 28, '梧州市');
INSERT INTO city VALUES (334, 28, '北海市');
INSERT INTO city VALUES (335, 28, '防城港市');
INSERT INTO city VALUES (336, 28, '钦州市');
INSERT INTO city VALUES (337, 28, '贵港市');
INSERT INTO city VALUES (338, 28, '玉林市');
INSERT INTO city VALUES (339, 28, '百色市');
INSERT INTO city VALUES (340, 28, '贺州市');
INSERT INTO city VALUES (341, 28, '河池市');
INSERT INTO city VALUES (342, 28, '来宾市');
INSERT INTO city VALUES (343, 28, '崇左市');
INSERT INTO city VALUES (344, 29, '拉萨市');
INSERT INTO city VALUES (345, 29, '那曲地区');
INSERT INTO city VALUES (346, 29, '昌都地区');
INSERT INTO city VALUES (347, 29, '山南地区');
INSERT INTO city VALUES (348, 29, '日喀则地区');
INSERT INTO city VALUES (349, 29, '阿里地区');
INSERT INTO city VALUES (350, 29, '林芝地区');
INSERT INTO city VALUES (351, 30, '银川市');
INSERT INTO city VALUES (352, 30, '石嘴山市');
INSERT INTO city VALUES (353, 30, '吴忠市');
INSERT INTO city VALUES (354, 30, '固原市');
INSERT INTO city VALUES (355, 30, '中卫市');
INSERT INTO city VALUES (356, 31, '乌鲁木齐市');
INSERT INTO city VALUES (357, 31, '克拉玛依市');
INSERT INTO city VALUES (358, 31, '石河子市　');
INSERT INTO city VALUES (359, 31, '阿拉尔市');
INSERT INTO city VALUES (360, 31, '图木舒克市');
INSERT INTO city VALUES (361, 31, '五家渠市');
INSERT INTO city VALUES (362, 31, '吐鲁番市');
INSERT INTO city VALUES (363, 31, '阿克苏市');
INSERT INTO city VALUES (364, 31, '喀什市');
INSERT INTO city VALUES (365, 31, '哈密市');
INSERT INTO city VALUES (366, 31, '和田市');
INSERT INTO city VALUES (367, 31, '阿图什市');
INSERT INTO city VALUES (368, 31, '库尔勒市');
INSERT INTO city VALUES (369, 31, '昌吉市　');
INSERT INTO city VALUES (370, 31, '阜康市');
INSERT INTO city VALUES (371, 31, '米泉市');
INSERT INTO city VALUES (372, 31, '博乐市');
INSERT INTO city VALUES (373, 31, '伊宁市');
INSERT INTO city VALUES (374, 31, '奎屯市');
INSERT INTO city VALUES (375, 31, '塔城市');
INSERT INTO city VALUES (376, 31, '乌苏市');
INSERT INTO city VALUES (377, 31, '阿勒泰市');
INSERT INTO city VALUES (378, 32, '呼和浩特市');
INSERT INTO city VALUES (379, 32, '包头市');
INSERT INTO city VALUES (380, 32, '乌海市');
INSERT INTO city VALUES (381, 32, '赤峰市');
INSERT INTO city VALUES (382, 32, '通辽市');
INSERT INTO city VALUES (383, 32, '鄂尔多斯市');
INSERT INTO city VALUES (384, 32, '呼伦贝尔市');
INSERT INTO city VALUES (385, 32, '巴彦淖尔市');
INSERT INTO city VALUES (386, 32, '乌兰察布市');
INSERT INTO city VALUES (387, 32, '锡林郭勒盟');
INSERT INTO city VALUES (388, 32, '兴安盟');
INSERT INTO city VALUES (389, 32, '阿拉善盟');
INSERT INTO city VALUES (390, 33, '澳门特别行政区');
INSERT INTO city VALUES (391, 34, '香港特别行政区');

前后台代码实现

• 所需工具

dom4j.jar -- 解析xml库
ojdbc6.jar -- 数据库驱动包

• entity，dao层实现

• basedao

package dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class BaseDao {
	static {
		try {
			Class.forName("oracle.jdbc.OracleDriver");
		} catch (ClassNotFoundException e) {
			e.printStackTrace();
		}
	}
	
	public static Connection getConn() throws SQLException {
		Connection conn = null;
		
		String url = "jdbc:oracle:thin:@127.0.0.1:1521:orcl";
		conn = DriverManager.getConnection(url, "scott", "scott");
		
		return conn;
	}
	
	public static void closeAll(Connection conn, PreparedStatement ps, ResultSet rs) {
		try {
			if (rs != null)
				rs.close();
			if (ps != null)
				ps.close();
			if (conn != null)
				conn.close();
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}
}

• citydao

package dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import entity.City;

public class CityDao {

	public List<City> queryCityByPid(int pId) {
		List<City> list = new ArrayList<City>();
		
		String sql = "SELECT * FROM CITY WHERE PID = ?";
		
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		
		try {
			conn = BaseDao.getConn();
			ps = conn.prepareStatement(sql);
			
			ps.setInt(1, pId);
			
			rs = ps.executeQuery();
			
			while (rs.next()) {
				City city = new City();
				city.setcId(rs.getInt("cid"));
				city.setpId(rs.getInt("pid"));
				city.setcName(rs.getString("cname"));
				list.add(city);
			}
			
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			BaseDao.closeAll(conn, ps, rs);
		}		
		
		return list;
	}	
	
}

• provincedao

package dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import entity.Province;

public class ProvinceDao {

	public List<Province> queryAllProvince() {
		List<Province> list = new ArrayList<Province>();
		
		String sql = "SELECT * FROM PROVINCE";
		
		Connection conn = null;
		PreparedStatement ps = null;
		ResultSet rs = null;
		
		try {
			conn = BaseDao.getConn();
			ps = conn.prepareStatement(sql);
			
			rs = ps.executeQuery();
			
			while (rs.next()) {
				Province pro = new Province();
				pro.setpId(rs.getInt("pid"));
				pro.setpName(rs.getString("pname"));
				list.add(pro);
			}
			
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			BaseDao.closeAll(conn, ps, rs);
		}		
		
		return list;
	}
	
}

• servlet

package servlet;

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;

import dao.ProvinceDao;
import entity.Province;

public class QueryAllProvince extends HttpServlet {

	/**
	 * 查询所有省会 加载到下拉框
	 */
	private static final long serialVersionUID = 1L;
	
	@Override
	protected void service(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		ProvinceDao dao = new ProvinceDao();
		
		List<Province> list = dao.queryAllProvince();
		
		Document doc = DocumentHelper.createDocument();
		
		// dom4j创建根结点
		Element root = doc.addElement("ProvinceInfo");
		
		for (Province p : list) {
			// 每个省级结点信息
			Element provinceRoot = root.addElement("province");
			
			provinceRoot.addElement("pId").setText("" + p.getpId());
			provinceRoot.addElement("pName").setText("" + p.getpName());
		}
		
		// 把内存中创建的xml转成string
		String provinceXml = doc.asXML();
		
		resp.setContentType("text/xml;charset=utf-8");
		// 以xml字符串的形式发送到前台
		resp.getWriter().write(provinceXml);
		
	}


}

package servlet;

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;

import dao.CityDao;
import entity.City;

public class QueryCity extends HttpServlet {

	/**
	 * 根据省会id查询城市
	 */
	private static final long serialVersionUID = 1L;
	
	@Override
	protected void service(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		Integer pId = Integer.parseInt(req.getParameter("pId"));
		CityDao dao = new CityDao();
		
		List<City> list = dao.queryCityByPid(pId);
		
		Document doc = DocumentHelper.createDocument();
		Element root = doc.addElement("cityInfo");
		
		for (City city : list) {
			Element cityRoot = root.addElement("city");
			cityRoot.addElement("cId").setText(city.getcId() + "");
			cityRoot.addElement("pId").setText(city.getpId() + "");
			cityRoot.addElement("cName").setText(city.getcName() + "");
		}
		
		String cityXml = doc.asXML();
		
		resp.setContentType("text/xml;charset=utf-8");
		// 以xml字符串的形式发送到前台
		resp.getWriter().write(cityXml);		
	}

}

• 前台页面

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'province_city_linkage.jsp' starting page</title>
    
	<meta http-equiv="pragma" content="no-cache">
	<meta http-equiv="cache-control" content="no-cache">
	<meta http-equiv="expires" content="0">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	
	<script type="text/javascript">
	
		function loadProvince() {
			
			var ajax = new XMLHttpRequest();
			ajax.onreadystatechange = function() {
				if (ajax.status == 200 && ajax.readyState == 4) {
					// 拿到下拉框
					var proSelect = document.getElementById("province");
					
					// servlet响应的xml对象
					var provinceXml = ajax.responseXML;
					// 获取xml的省会结点
					var provinceArr = provinceXml.getElementsByTagName("province");
					
					for (var i = 0; i < provinceArr.length; i++) {
						var pId = provinceArr[i].firstChild.firstChild.nodeValue; // 这里取结点根据你的xml结构来取
						var pName = provinceArr[i].lastChild.firstChild.nodeValue;
						proSelect.add(new Option(pName, pId));
					}
				}
			};
			
			ajax.open("get", "QueryAllProvince", true);
		
			ajax.send();
		}
		
		loadProvince();
		
		function loadCity(pId) {
			if (pId == 0)
				return;
			
			var citySelect = document.getElementById("city");
			
			citySelect.length = 1;

			var ajax = new XMLHttpRequest();
			ajax.onreadystatechange = function() {
				if (ajax.status == 200 && ajax.readyState == 4) {
					var cityXml = ajax.responseXML;
					var cityArr = cityXml.getElementsByTagName("city");
					
					for (var i = 0; i < cityArr.length; i++) {
						var cId = cityArr[i].firstChild.firstChild.nodeValue;
						var cName = cityArr[i].lastChild.firstChild.nodeValue;
						
						// 下拉框值在后, value在前
						citySelect.add(new Option(cName, cId));
					}
				}
			};
			
			ajax.open("get", "QueryCity?pId=" + pId, true);
		
			ajax.send();
			
		}
	</script>

  </head>
  
  <body>
    <select id="province" onchange="loadCity(this.value)">
    	<option value="0">请选择省会</option>
    </select>
    
    <select id="city">
    	<option value="0">请选择城市</option>
    </select>    
  </body>
</html>

最原始的方法…